Partygoers preferred to pop pills than pay for pilsners at a Sydney rave where one man died and at least 20 others overdosed on drugs.

One reveller said it was cheaper to buy drugs than pay for alcohol at the Defqon.1 music festival, which drew more than 18,000 dance fans to the Sydney International Regatta Centre near Penrith on Saturday.

An artist manager who attended the event said people were ‘‘downing’’ drugs at the start of the festival to avoid arrest.

‘‘Punters who intend to bring a few pills with them in case they feel like taking them across the course of the day are now forced to down everything at once in order to avoid possible arrest,’’ she said. ‘‘This is costing young people’s lives.’’