Underground Comix are known for using different prices, covers (art or color variations) and/or interior content to distinguish between printings.
1st print August 1979 has 1.00 USD cover price. Both say which printing in indicia information.
2nd print June 1981 has 1.50 USD cover price.
2nd print is indexed here.
Inside front cover with illustration, credits and indicia information.
Story ends on back cover in color.