bidwars suggest that the player is currently UNDER market value, because no one should put their personal max bid as their first bid when theres a shot you could get him for less, its a horrible strategy
if the deadline didnt extend, someone could wait until the last second and outbid you and you wouldnt get the opportunity to bid back at him even though you definitely would have paid more UP TO the actual market value
yes, occasionally it could go higher if someone goes on tilt after 10 minutes of bidding, or if someone is desparate due to injuries, but i believe thats a much lesser evil than my previous point and happens a lot less