If you check my screenshot you can see that there are no shops left. I bought everything. My shop luck wasn't outstanding, I just bought a lot of stuff. Transmuting MW gave 50 gold, and I earned another 40 from TT's boons. Usually it's unnecessary, bot none of my subs gave gold. One of them was the monster zoo, the other is the curse plan - wisp charm sub.
When using this strat it helps a lot to pick extra gold too.
Btw my CP was exactly 1260. I checked it, because I wanted to calculate if it's better played as a Gnome with his 14 extra mana potions instead.
Edit: Didn't explain my piety. It's achieved by peakabooing. I basically explore close to the entire floor spamming cheap JJ friendly glyphs (this time Apheelsik), while hitting a group of 3 monsters with bearmace into blackspace. Each time I rediscover them I get a lot of piety. Played this way, JJ is one of the best piety farms.
Edit2: Was in a rush, didn't read your last comment carefully Darvin. Should have mentioned that I converted those 4-5 wisp gems, 4 potions, obviously the bearmace and to be honest my shop pool was good:
http://postimg.org/image/9u5mdhyeh/Though for this strat CP ratio is less important, you're primarily looking for items with big CP value.