Instead of 40% gap why not just award player to the team with the highest bid value based on total value of the bid (i.e. transfer fee + [weekly wage x 18 wks/season x no. years in contract offered]). This seems like it would be better with new transfer limitations
for example:
Bid 1: 500,000 transfer fee, 3,000 G weekly wage x 5 seasons
Bid 2: 300,001 transfer fee, 3,001 G weekly wage x 2 seasons
With proposed system, bid 2 would win...for me this is silly because the total value of bid 2 amounts to as little as 53% of bid 1 depending on length of contract:
500,000 + 3,000 x 18wks x 5 seasons = 770,000 total bid worth
300,001 + 3,001 x 18wks x 2 seasons = 408,036 total bid worth
With my proposal, the following transfer/wage offers would be needed (assumes 5 year contract) to beat bid 1 (above):
transfer fee weekly wage total value
300,000 5,300 777,000
400,000 4,200 778,000
450,000 3,600 774,000
Basically, with a transfer fee set at 40% lower than highest, weekly wages would need to be between ~75% (5 year contract) and 188% (2-year contract) higher!
This seem far more reasonable imho...
To compliment this, the length of time in which the transfer tax drops from 65% to 20% should be based on the length of the contract signed. I think 10-15% of the contract length is reasonable. If we assume 18 weeks (126 days) per season, this time period would be 25-38 days for a 2-season contract and 63-95 days for a 5-season contract. This would curtail players making insanely high wage bids to win the player, since they'll be stuck with the player (and his wages) for considerably longer with longer contracts that factor in the bid's total value.