Underground Comix are known for using different prices, covers (art or color variations) and/or interior content to distinguish between printings.
The Print Mint-
1st print has 0.50 USD cover; 2nd print- 0.75 USD; 3rd print- 1.00 USD
Last Gasp-
4th print- 2.00 USD; 5th print- 2.50 USD cover (not listed in Fogel's guide)
6th print- 2.95 USD; 7th print- 3.95 USD
This issue has variants: