Underground Comix are known for using different prices, covers (art or color variations) and/or interior content to distinguish between printings.
1st print has no cover price. 2nd print has 2.50 USD cover. 3rd print has 2.95 USD cover.
4th print has 3.95 USD cover.
This issue is a variant of Zap Comix (Last Gasp, 1982 ? series) #12
There exist further variants: