I do a ton of stealing and the real cost is time spent clicking. And if you really get into setting up stealing runs there are big rewards but it's debatable how efficient it is. This is because BG3 basically implement tiers of play rewards, time spent stealing low level stuff is not time spent getting mid/high level stuff.
Or put another way, in 50 hours you could be blowing through Act 2 with its better vendors, or still mucking around with Act 1 vendors.
