Basically FI change the range whenever they want.
It was meant to be 60% (minimum) of buy price. Then customer services told me it was 40%. Now I have some players with bids as low as 32%.
They could put a stop to this race to the bottom if they wanted. But imposing a strict say 70% minimum could just highlight the massive lack of liquidity in the market, as thousands of players would be left with no bid. That or buyers would just increase their bids to the minimum 70% level and the balance between buyer and seller would be better and the market healthier.