I only use the Mercury oil even though I think most of it is the same. Just to preserve warrantees and so on...Anyway I try to stock up at Costco at $11 per gallon last time I bought it. It is really unpredictable when they have it though. No stock so far this year. GI Joes has it on sale from time to time but they will probably not have any stock 5 minutes after the ad runs....They don't do rain checks but will take a "special order" for the sale price and notify you when it is in.