The people undercutting the chest prices are people reselling their used
chests. Not ususaly merchants selling chests. Since chests almost never leave
the game there will always be none-merchants with chests for sale cheep
This might be fixable if there were less chests produced and merchants always
bid on the chests sold by none-merchants such that chests were never sold
under the mininum price. But that would require a rich merchant who cared
about hte price of small chests... Oh, and chizra is a bitch.