I think you misunderstand me. There is no way that the 20% sell on clause helps us in any way as someone else seemed to be suggesting, yes 20% of £60m is more than giving away 20% of £50m, but so is the 80% that they keep...
There's no tipping point where Palace turn round and say, "whoaaa boys, we don't want any more than that, in fact offer less if anything..."
Bottom line is that the bigger the bid, the more money Palace get, they have no reason to minimise the fee. I was actually agreeing with your point initially, there's no reason why Palace would just see 2x their original outlay as fair and sell for that, they will simply get as much as possible.