If you're game to pull it and reinstall it yourself, you may find a local tranny shop that would do a reasonably priced rebuild on a carry out. Of course, you're still probably looking at $400-$500 in parts once you include swapping out for a reman torque converter plus the build fee on top.
Still, if you're looking at $400-800 on a used trans... I'd very seriously consider that option. I personally will almost never install a used tranny just due to the complete PITA of pulling and installing one, compared to the work/cost of rebuilding one. Granted I do all my own, but even to pay someone I would consider the return on investment to well worth it compared to the risk of installing a used trans that may be near the end of its life. Of course you can mitigate some risk by popping off pans and inspecting the fluid and particulates in the pan, but this is not always conclusive as even in the scrap yard someone may have tried a last ditch tranny fluid change before sending their own vehicle off to be junked, or the occasional unsavory character who would try to clean up the pan and dump in newer fluid to make the trans look better than it is.
I would look at the amount of time you would spend looking for another trans, going to inspect possibly a couple of transmissions, pulling the trans yourself if in a pick and pull lot, and then I would add 50% more time again to account for risk of getting a bad used trans and having to go thru the process again. Calculate how much you would make had you spent the same time working at your job or on a side job, and compare that to the increase in cost of a reman trans.
At the end of the day nobody knows your situation better than you, so do what you feel fits your situation best, but from my experience this is the advice I would give. Best of luck and Merry Christmas!
