This is a flip book with two covers.

The on-sale date is the publication date reported in U. S. Copyright Office filings.

Underground Comix are known for using different prices, covers (art or color variations) and/or interior content to distinguish between printings.
1st print has 0.50 USD cover. Has heavy stock cover.
2nd print has 0.50 USD cover. Has regular weight cover stock.
3rd print has 0.75 USD cover. 4th print has 1.00 USD cover. 5th print has 2.00 cover.
6th print has 2.50 USD cover (published by Last Gasp). 7th print has 2.95 USD cover.
8th print has 3.95 USD cover. 9th print has 4.95 cover.