This could be a tactical aspect too that you bid 20 tokens and by this you fear your opponents not to bid anymore. Because most of the times those 20 tokens are minimum to buy something. I dont know how you can buy something with 1t nowdays, maybe 3star player. With previous market system you could buy players with 1 token but not with current.
Or another one could be that bots are bidding. That's another theory.
Third - they do not care how much tokens they spend in order to buy a player.