I've never encountered this bug before. Did you have a high enough balance? And what browser were you using?
Edit: I've tested it on Firefox, Chrome, and Edge, and have been able to purchase the guns.
I was able to purchase the gun but it didn't change the gun in the coffin. Perhaps it's a bug on my end only lol
Use Q and E to switch guns. It's in the game's controls page.
I probably should have made it so the game automatically switches to the most recently purchased gun, sorry for the confusion.
