Used propane tanks. Most are empty but some have a little propane in them. Six 20lb tanks and two 30lb tanks. 20lb tanks are $15 for one, $25 for two. Better deal if you by more. 30lb tanks are $25 each but needs to be re-certified as they are over the 12 year manufactur date. Some of the 20lb tanks may be past the manufactur date so you might not be able to refill them but you can exchange them at Walmrt's self serve propane exchange machine.