Amazed how none zelda game is here, TLOZ shop theme, Malo Mart, majora's magic hag's potion shop are such a bangers.
(https://youtu.be/Hb-ZF6ajmuQ)
(https://youtu.be/LepGlDFhcKM)
(https://youtu.be/-Hkio9W2osA)
I never played any Digimon World but i really like the DW2 shop theme.
(https://youtu.be/23RTrNUCQA0)
Ronde OST sucks in general, but Shop 2 is really great.
(https://youtu.be/qzbzGEzb0T8)
And now taking advantage since im talking about MegaTen, SMT Nine shop theme, SMT IV black market and P3 Tanaka's amazing comodities are pretty catchy.
(https://youtu.be/jbo4_GLouZM)
(https://youtu.be/-7M_g_LJn3Q)
(https://youtu.be/BUVuOIuKl3c)

https://www.youtube.com/watch?v=k7pypOQYppM

Thanks for the suggestions, I would have probably remembered to include SMT IV and P3 myself if I did this list less late in the night lol

Persona 5 Strikers

Ring Fit Adventure has one theme for each of it's shopkeepers, and it harmonizes when they're together.

Malo Mart is a masterpiece lol. I haven't played Earthbound yet but isn't Buy Something Will Ya a shop theme?

Crypt of the Necrodancer lol

i was going to discuss some technicalities, but just have the sims shopping music instead
https://www.youtube.com/watch?v=399YneFTwh0

and idolm@ster 2
https://www.youtube.com/watch?v=7pmadF1TSE4

Evergrace's shop music is absolutely wild and I love it.
https://www.youtube.com/watch?v=WGJbuHUbw8k

Spelunky's Black Market has some great music to buy illicit goods to.
https://www.youtube.com/watch?v=lhgyR2yP1b8

supporting the P5S suggestion

Thanks for the suggestions again. That Evergrace shop theme is so weird and I can't decide whether I like it or not lol

Shantae & The Pirate's Curse

classic
https://youtu.be/aYqjFAz6Is4

jets n guns (both 1 and 2) shop theme slaps and I'm devestated it's not on here
for reference:
https://www.youtube.com/watch?v=UAk0mwjZ_Rc
https://www.youtube.com/watch?v=IL2x1-DB498

ITADAKIMASU - No More Heroes 3
https://youtu.be/jdkTdaNJsvs