Established players such as Sergio Ramos and Arda Turan are grabbing most of the headlines but, as the transfer window officially opens on Wednesday, here is a reminder that not every good signing has to cost more than £20m.

Henri Bedimo (Lyon)

Age 31 Position Defender Apparently out of favour at Stade Gerland after the arrival of Jérémy Morel from Marseille, the Cameroon international would add steel to many mid-table defences – Watford and West Bromwich Albion have reportedly registered interest. The 31-year-old also likes to get forward and has plenty of pace. He is out of contract in 12 months so the Lyon manager, Hubert Fournier, may want to let it him go now rather than on a free. He could represent good business at around £3m.

Morgan Sanson (Montpellier)

Age 20 Position Midfielder He suffered a knee injury in April that will likely keep him out until a few weeks into the season but has plenty of suitors including Milan and Lyon despite that. He possesses a natural flair and craft which could be developed into something clinical but the downside is he often attempts to take the opposition on by himself and could be accused of failing to play the easy pass. However, at 20 and with the right manager that can be easily remedied. Fitness concerns aside, he could be a worthwhile gamble at around £5m.

Oscar Hiljemark scores Sweden’s fourth goal against Denmark at the Under-21 European Championship. Photograph: Carl Recine/Reuters

Youri Tielemans (Anderlecht)

Age 18 Position Midfielder He is already linked with some big destinations, including Chelsea and Arsenal, and it may be wise to take a punt on the 18-year-old now before his stock rises further and the fee inflates. The midfielder has been named Belgium’s young player of the year in each of the past two seasons and played in 35 of Anderlecht’s 40 Pro League games last season. He is valued at around £15m and, while this is pricey for a teenager, if he keeps developing at the present rate, it will not be long before far greater sums are being discussed. Wisely Anderlecht have him tied to a contract until 2020.

Oscar Hiljemark (PSV)

Age 22 Position Midfielder Entering the Under-21 European Championship after a solid campaign at PSV, who signed him from Elfsborg in 2013 with an eye to replacing Kevin Strootman, the Sweden captain has impressed in centre midfield in the Czech Republic. Composed and comfortable playing in a holding role as much as when taking a more advanced post, he would represent a decent punt at around £5m even if he might require some work before becoming the finished article. He has broken into the senior international side and is contracted until the end of next season.

Bernd Leno (Bayer Leverkusen)

Age 23 Position Goalkeeper If David de Gea departs Old Trafford, Manchester United could do far worse than cast an eye over the Bayer Leverkusen No1. The sheet was kept clean in half of his Bundesliga appearances last season and he also shone in defeat against Atlético Madrid in the Champions League, dragging his team to a penalty shootout almost by himself. He could cost in the range of £15m but that would still leave some additional spending money for Louis van Gaal to strengthen elsewhere.

Raphaël Guerreiro (Lorient)

Age 21 Position Defender An impressive feature on the left side of the Portugal Under-21 defence at the European Championship, he is being courted by several Ligue 1 clubs after securing a starting place in his second campaign at Lorient. He scored seven times last season and was Lorient’s most-used outfield player; he has often played on the wing. One concern is that he is slight and may struggle against physical opponents. He is valued at around £7m and his stock is only going to rise. Born in France but with a Portuguese father, he could not speak the language when initially called up to the Portugal Under-21s in 2013; he is now on the fringes of the senior side. He has under two years remaining on his current deal.

Charles Aránguiz played for Chile at the 2014 World Cup. Photograph: Gabriel Bouys/AFP/Getty Images

Charles Aránguiz (Internacional)

Age 26 Position Midfielder For Chile he is unlikely to feature as prominently in the hype stakes as Alexis Sánchez and Arturo Vidal. But having impressed in last summer’s World Cup before doing so again at the Copa América, the midfielder could add steel to a choice of Premier League midfields. Yet to feature in Europe, despite signing for Granada who subsequently loaned and then sold him to Internacional, he does not carry as inflated a price tag as similar players and could be lured for a shade over £10m.

Aleksandar Mitrovic (Anderlecht)

Age 20 Position Striker The Serb’s price tag has already risen but, similarly to his club-mate Tielemans, it will only continue on an upward trajectory, meaning any value could soon be gone. Anderlecht broke their transfer record to sign him two years ago for €5m (£3.5m) and they have already had a handsome return. He scored 14 in his first Pro League campaign and broke the 20-goal mark last season. Powerful and with a ferocious shot the 6ft 2in striker can be deceptively quick. He recently broke into the senior international side and Anderlecht would be happy to sell for around €15m; the player harbours Champions League hopes.

Terence Kongolo (Feyenoord)

Age 21 Position Defender Strongest at centre-half but also capable of covering at left-back, he went from the fringes to being a key component of Feyenoord’s defence last season after emerging from the club’s prolific academy in 2012. He was part of Van Gaal’s Holland squad at last summer’s World Cup but played only in the final minute of the group game against Chile. He may be tempted to follow his younger brother Rodney, currently at Manchester City’s academy, to England. His current deal runs out in June 2017 and he would cost in the region of £7m.

Richie Towell (Dundalk)

Age 23 Position Midfielder An attacking midfielder with a penchant for the spectacular, Towell may follow other unpolished gems who start in Ireland before starring in the Premier League, such as Shane Long, Séamus Coleman and Wes Hoolahan. He led Dundalk to a first league title in 19 years last season and has been watched closely by a host of Championship clubs for some time. For the money-conscious he could represent a very shrewd piece of business at around €200,000 (£140,000). Dundalk play Bate Borisov in the Champions League qualifiers next week – it may be the stage where many more take notice.

Terence Kongolo plays for Holland in a friendly against Ecuador. Photograph: Charlie Crowhurst/Getty Images

Karol Linetty (Lech Poznan)

Age 20 Position Midfielder The Poland midfielder was outstanding in his club’s league title-winning campaign last season, becoming the first name on Maciej Skorza’s team-sheet. Robert Lewandowski was impressed after Linetty’s recent involvement with the international side and he could be valued at around £2m. He would likely require some polishing but at such a good price could be a worthwhile gamble.

Anwar El Ghazi (Ajax)

Age 20 Position Midfielder He won the talent-of-the-year accolade at his club after a season when he reached double figures in goals from the wing in 43 appearances and the 20-year-old’s form has already alerted several of the world’s biggest clubs. Rapid and with a penchant for cutting in and unleashing missiles towards goal, the Holland Under-21 player, who could also represent Morocco, is another whose market value will likely rise exponentially over the next 12 months. But he could be available now for around £7m.