Craigslist/Allofcraigs might be your friend. Trans jacks are on there frequently.
I bought a Carolina brand trans jack maybe 15 years ago at a local auto parts store. Paid about $200 as I recall. Good quality, and has removed and reinstalled a good handful+ of transmissions for me.
Then, there is the dreaded Horror Freight option:
http://www.harborfreight.com/800-lb-capacity-transmission-jack-3185.html
That one looks like a very similar design to my Carolina, which might also be of Chinese origin, I am not sure.
I have one of those adapter plates that you can attach to a floor jack to make it a trans jack; I never used it. If you want it for cheap money, let me know.
Bottom line: you have options.