If you google "rv covers" you'll see a number of options. I would think "best" price might change according to sales, shipping costs, etc. CW always has a sale in the fall, but I don't know whether that is still running or not. Fwiw, I like my Adco Tyvek cover, and thought the price was pretty fair 6 years ago.
Jayco Designer 30 RKS Medallion pkg, Trail Air pin
'05 F350 6.0 PSD CC 4x4 DRW LB B&W Companion, Edge Insight
โCertainly, travel is more than the seeing of sights; it is a change that goes on, deep and permanent, in the ideas of living." Miriam Beard