Both great covers, but one involves a calendar and the other a menacing/looming joker brandishing two guns. I think people gravitate toward the violence/danger associated with 69 more so then 71, same reason TEC 62 (joker holding ballons) probably never reaches the levels of a TEC 69 (or TEC 71) - my two cents.
Anyway, the TEC 71 CGC 8.0 for sale in the next HA auction should tell you what you want to know in terms of value, though no one knows what a TEC 69 CGC 8.0 would go for these days.
I am sure it would be eye popping.
What about the price jump of Tec 69 trickling down to Tec 76? Last November a CBCS 8.5 copy of Tec 76 sold for an eye popping $11,352!