The Onion explains why the people of Felltower are so wary of the PCs:
Video Game Shopkeeper Starting To Get Suspicious After Selling 800 Bombs To Player
Yep, that's Felltower, right there.
"Hmm, that guy cleaned me out of alchemist's fire, paut, healing potions, and dark vision eye rub . . . and last week he was selling 'crab legs' and blood-stained weapons and weird idols and was pretty cagey about where it came from."
This is why the PCs don't all have a +4 reputation as generally great guys who spend a lot in town. Oh, sure, they spend a lot in town, but how they get that cash and what they spend it on, well, it's like a guy who comes to the pawn shop with a bunch of antique gold and then swings by Wal*Mart and cleans them out of ammo, sterno, and pressure cookers . . . and repeats that week after week. You're going to be regarded with some concern.