Instead of renting, it would probably make more sense for you to buy the tool, use it for a while, and when you're done with it, resell it on Craigslist. Given all the hassle that goes with renting (as you mentioned), reselling on CL is probably no more hassle. And you'll wind up saving a lot of money too.
That said, I do think there's something off about my accounting. I live in SF - the tool may cost X dollars, but what's the yearly rent on the square footage that the tool occupies? Just to sit there unused 99% of the time.
I'm starting to rent things not because it's cheaper but because I'm beginning to understand the psychological effects of having too much clutter in a relatively small house.
But yeah, renting is really expensive with all kinds of little gotchas, and it's a surprising hassle, too. Almost as much of a hassle as having a lot of clutter around.