A few quick comments:
You don't need to spin the wheel many times in a combat situation. Once is enough, usually, so those seconds of tension are much better invested than the 15-30 minutes it usually takes to kill a kobold.
Roulette wheels can be bought cheap - childrens' toys - or used. I got mine for about $1.50 - and it even came with a board game with heaps of monopoly money
I was skeptical about the roulette wheel before I read the game - not anymore, though.