|this is my hell|
Inventory slots can be filled with 'Adventuring Gear' for, I dunno, 30 coins each. This is assumed to be torches, iron spikes, blankets, sacks, food, sacks, chalk, 10 foot poles, ropes, lantern oil, cooking pots, small mirrors- just 'stuff' that is handy to have in a dungeon. Once you actually use gear as such, replace the generic 'Adventuring Gear' with what you actually used on your sheet (or cross it off if it was consumed.) This also means that players will have to get more creative on longer delves- at the beginning, they can say they have exactly what they need, but then deeper in, the amusing improvisation of 'how can we do X with only a wire, a mirror, and a sack of sausages' will still get some love.
Goals I hope this accomplishes- allows players to do typical dungeon problem solving without having to spend actual hours of actual peoples actual lives counting how many pieces of chalk they are pretending their pretend elf has.
I am also thinking about how to tie it to resource and time management. Eating food and light sources burning down as you search a room carefully and using a rope as a grappling hook all take away Adventuring Gear slots. I think the palpable effect of actually crossing off things from character sheets will actually give players a sense of urgency that secret wandering monster rolls just don't accomplish.
Also, one thing thieves could be good at is spending 'adventuring gear' to disable traps, bypass locked doors, find secret hidden things, etc not by percentile rolls, but by resource management. Thiefly stuff is often pretty abstract in resolution(which is why rolling to pick a lock rather than 'describing how you pick a lock' is a thing) so I don't think this is too 'gamey.' Hirelings carrying loads of 'Adventuring Gear' so the thief can demolish locked doors sounds like a feature, not a bug.
Thieves are for sequence-breaking. Thieves are for saying 'you know what, I'll pick the lock instead of recover the vault key from the neck of the guardian beast. Or steal the key from the guardian beast without ever waking it up. Or ignore the locked door entirely and climb up the outside of the tower and go in through a window.' All in opposition to the 'proper' sequence of
>fight guardian beast
And I think that's great.
One form of shopping I found interesting is the 'Institutions' section of The Nightmares Underneath.
In part this is because institutions becoming prominent as money is spent on them is an easy way for players to affect the world, and also because those institutions offered interesting things to spend your money on- poisons, treasure maps, printed slander, animals of specific quality breeding, and so on. Attaching consequences to shopping beyond 'you lose 17c and gain 10 candles and a magnifying glass' is a really fun idea (though not one that bypasses my problem of many shopping sprees being lengthy exercises in tedium).
Another way to bypass shopping is if there is no 'generic' shopping. The players must use manticore tail spikes instead of iron ones, save giant spider webs for ropes and hammocks, and loot anything and everything they can, not because it is worth a few coppers in 'town' but because they can think of a creative use for a broken chair in regards to the environment. This requires both heavy environmental descriptors and a setting where civilization is absent, but I really like the idea and feel like it could help foster and reward creativity in a big way. I wonder if this sort of hardcore scavenging/survivalist play is what the Veins of the Earth was getting at. Similarly, that would make wandering merchant encounters pretty interesting if there was no default source of generic equipment.