After the recent update for Spelunky on PlayStation Vita which added the terrific Daily Challenge mode and addressed a few issues like slowdown, I can wholeheartedly recommend double dipping with that version. Sony is currently doing a "12 deals of Christmas" promo in Europe and today, the game is marked down alongside Diablo III for PlayStation 3.
Spelunky for PS Vita (and PS3; Cross-Buy and Cross-Play are supported) is down to €6.99/£5.49 from its original price of €14.99/£11.99, and PlayStation Plus members can take an extra 10 percent off as well. As for Diablo III, it's cheaper, but still not particularly cheap -- the game is €39.99/£29.99, down from €59.99/£49.99.
The 12 deals of Christmas -- deal #2 [EU PlayStation.Blog]