Unless i'm reading it wrong,the 90 points to be paid for without any wage guarantee's at all i would of thought that most riders are on some sort of guarantee at the moment, plus some £ per point.
So with just points money to pay, you would end up with the worlds top riders and some of the GP stars wanting £400 + a point going down to the reserves at say £130 pp.
I don't see it making things cheaper and if you didn't pay the top guys top money,they won't come over.
Your idea might be workable in a lower league,but can't see it in the Prem.Just imho.