Well if you didn't cast shatter on the walls...

Now the adventure is about acquiring the land rights for this new gold mine, before anyone else. The guide is the only one, other than the party, that knows of the gold.

The easy fix to this is to just have no shops stock anything worth buying. In one of the campaigns I'm in the party is probably more wealthy than a small country but it's a rather low magic setting so you can't just buy magic gear or items. We've been investing in real estate and staff instead. But money is now far less important to the party than exploration in search of things we want and doing things for our favorite NPCs.

Also we have killed people via inverting a bag of holding full of money. Everyone loves the idea of receiving 500lbs of gold until they receive it suddenly from above at terminal velocity.

Endbosses are always load-bearing :)

Time to sell the rogue into slavery.