If only the valuation of players was an exact science. Instead, issues of fitness, form, the desperation of either the buying or selling club plus contractual status play a part. Sometimes they combine. In a fluctuating player-club power struggle salaries don’t multiply to the extent of desired transfer fee in the case of a meteoric rise. Where Celtic and Moussa Dembélé are concerned, a high price tag links to great debate; should Scottish football’s lowly status negatively impact on the value of a player when pursued from England?

What a wonderful alliance this has been. Dembélé has proven how Scotland – and particularly the Old Firm – can be a highly profitable calling point for a developing star. This applies to mindset more than technique; the insistence on constant success at Celtic and Rangers is significant to a level not regularly matched elsewhere.

The gulf in wages to England’s top flight is offset by prominence that, placed in context of the poor standard of at least half of Scotland’s Premiership, isn’t particularly plausible. The ease with which supposed £10m players depreciate should be a cause for amusement: Stefan Johansen, Nir Bitton, Emilio Izaguirre and Beram Kayal from recent times to name but four. Dembélé, though, shows no sign of toppling from his pedestal.

He has nine league goals this season, the same as Motherwell’s Louis Moult and Jamie Walker of Hearts. The Frenchman’s team-mate Scott Sinclair and the Ross County striker Liam Boyce can be found ahead in that chart. Celtic strikers, needless to say, are the best served.

As if to prove lies, damned lies and statistics, Dembélé clearly stands out as the blue-chip asset in Scotland. His outstanding display against Manchester City in the Champions League in September rattled Pep Guardiola’s men and they didn’t seem to recover for weeks. Dembélé displayed pace, power and overall attacking impetus that conjured images of the world’s finest centre-forwards. His hold-up play was exceptional.

Two other thoughts occurred: why no top-division club geographically closer to Fulham took a chance on this player before Celtic capitalised on a cross-border £500,000 development fee, and how an individual who laboured during his early weeks in green and white had so radically come of age. Even Dembélé’s later anonymity in a key match against Borussia Mönchengladbach and spurning of a key chance when Barcelona visited Celtic was ignored; with youth comes inconsistency, perhaps.

Celtic have been adamant they won’t sell Dembélé this month and the player hasn’t agitated for a move, yet the 20-year-old’s name remains on so many lips. West Ham United’s suggestion of a £20m bid was met with disdain in Glasgow. The private insistence on £30m being required to coax Dembélé from Celtic brings the former Paris Saint-Germain youth player into the same category as Diego Costa. Chelsea found that out when noting interest in Dembélé on Monday. Dembélé’s status has been further endorsed by standout performances for France Under-21s, during which his composure in front of goal has noticeably improved.

Moussa Dembélé scores his Celtic’s second goal in their 3-0 Scottish Cup fourth round win against Albion Rovers. Photograph: Jeff Holmes/PA

Barring a serious injury, Celtic hold all the aces here, as well they know. Centre-forwards are the transfer market’s prime commodity. The club is under no pressure to trade and Dembélé’s value surely cannot drop massively between now and the next window. Dembélé’s progress also enhances Celtic’s appeal to players of similar age and ambition. Victor Wanyama, Fraser Forster and Virgil van Dijk have followed the same route to the Premier League – and successfully.

Still, the exact-science notion can be readily exposed. Just as Celtic wouldn’t offer £1m for the best player at Bala Town or Cliftonville, the insistence that Dembélé’s value must be independent of domestic environment is nonsensical. This relates to the Championship as much as the Premier League; Ross County, Kilmarnock, Motherwell, Hamilton and Inverness wouldn’t survive in England’s second tier and nor should they given the budgetary chasm even relative to Rotherham and Barnsley. Celtic quite rightly didn’t pay £7m for Van Dijk or Wanyama when tempting them from Holland and Belgium respectively.

More curious still is the means by which Dembélé’s star hasn’t so much risen as entered a new stratosphere. Brendan Rodgers has a track record of developing talent, yet for a player to escape the clutches of England’s leading lights but be valued among football’s aristocracy within months isn’t particularly logical. Dembélé wasn’t exactly a secret when at Craven Cottage. Tottenham Hotspur were the closest to taking a gamble on Dembélé from Fulham; the circumstances by which that move didn’t transpire are not particularly clear. Either a host of scouting departments now have egg on their face, Dembélé has made bewildering progress or attention outweighs reality.

It is likely to be the summer before the answer to that conundrum is known. When Dembélé moved north, there would have been a preordained timescale for his departure. Just as Celtic are entitled to cherish Dembélé and the man himself to revel in this journey, what happens next is a legitimate cause for deep fascination.