We use Tonycolyer (aka hospitalitytextiles) and have also bought stuff from ChinoHouse and Johnbatman
Colyer has fitted sheets 1/2 the price of anyone else, Chinohouse we bought flat sheets from (bigger size than standard queen and only around $15) Johnbatman has some bargains sometimes (pillow cases were $1.29) All commercial quality and very good stuff.