This issue is a variant of Dr. Atomic (Last Gasp, 1972 series) #1 [1st print 0.50 USD]. There exist further variants.
Underground Comix are known for using different prices, covers (art or color variations) and/or interior content to distinguish between printings.
1st print (September) 1972 has 0.50 USD cover price.
2nd print (January) 1975 has 0.50 USD cover price and believed to be indistinguishable from 1st print.
3rd print 1977 has 0.75 USD cover price.
4th print 1978 has 1.00 USD cover price.
5th print has 1.25 USD cover price.
Inside front cover sequence with indicia information at bottom of page.
Dr. Atomic's programming for the robot is based on Asimov's three laws of robotics.
Inside back cover.