if you're not looking to cheat, you can find a nearby bench and just wait for 48 hours, they'll reset after that and have full money stocks again. but otherwise the vendors are way too broke in this game.
Personally, i got that same copy, the only bug i've encountered has been a missing housing that a robot would sit in, but the computer to control the robot was just floating next to it. I've always had weirdly good luck with Bethesda games though, so it's not surprising for me i've had an almost bug-free experience