Thanks to everyone for their input, it was all really helpful.
I agree that perhaps patience would have turned up a cheaper option than my $35 CL purchase, but we are under a time constraint because our city's bulk pickup is coming up and we wanted to get rid of the old rotten bits asap. As for shopping more aggressively, I am in a large metro area, and didn't see a lower price anywhere within a two+ hour round trip drive. Saving 15 dollars isn't worth spending two or more hours in my car. This one I was able to pick up on my way to somewhere I already needed to go, at a time that was convenient to me, so in my book it was an easy choice.
I must thank J Boogie for even mentioning CL. As much time as I waste spend perusing this forum, it didn't occur to me to look there first, and I'm glad I did. The saw we got served us very well, and by the time we were done, a new one would have looked about like this one did, so it was money well saved.
Paddedhat and Spork, I really appreciate the recommendation for blades. I picked up a five pack of the Lenox demolition blades, and it was enough for our job. We didn't break any, but it was nice to be able to replace them at a reasonable frequency to be sure we weren't courting trouble.
FWIW, I'm not sorry to have purchased over renting. We have a lot of trees with very hard wood that require regular maintenance, and this baby will be able to slice through them in no time, so I think we'll be able to use it again in the future.