By Matt Hardy Swimmer James Magnussen, the first athlete to sign up for the Enhanced Games, admits that a $1m prize was the “tipping point” to agreeing to take part in the so-called doped Olympics but insists his decision was not just about money. Magnussen, a former world champion and Olympic medallist, is coming out of retirement to compete in the Enhanced Games, the brainchild of London-based Australian Aron D’Souza and backed by PayPal founder Peter Thiel which has promised him $1m if he breaks the 50m freestyle world record. “Anyone that comes out and says that the money is not a factor w…