RE: how much?
Remember you get what you pay for. There are other things to consider, for instance, brakes. You can go cheap with some scrubber type brakes, but the first time you have to abort a takeoff, a good set of brakes will pay for themselves (don't ask how I know, my thumbs forget they are there [&o].
Some deals can be had - right now I'm re-building a wrecked Super Reaper. I bought it for $500, with a new set of retracts. I sold the retracts on Ebay for $450, so I now have a cheap jet. It will be a little ugly, but it's going together to be a beater jet. My first Reaper was uglier, but flew just fine with a P-80. I'm hoping my T-500 will fly it OK.
I'm thinking a Baby Boomerang, with a 12 to 14 pound turbine. Should be the best value for the money.
Just my opinion, Mark