Having the contender "sickness" like many around here, I can tell you this...that deal sounds kinda fishy...
As others have said...cheapest I have seen a frame and barrel go for was 350 and that was a frame with a trigger issue (someone tried to massage it into a target trigger and instead made a dangerous situation, so he tried to sell it off). I am happy to say that Thompson Center Arms was more than happy to sell me a trigger at an extremely reasonable price.
Simple test is to set the action (break and close) then pull the hammer back, then slap the base of the pistol grip in the palm of your hand...if the hammer doesn't fall, then your sear engagement is good as well as your spring tension for the same. inspect the bore for throat erosion...there should be a well-defined shoulder inside the chamber...you will have frame marks on the barrel...break the action as to load it, then try to wiggle the barrel to see how much frame stretch there is...357 mag shouldn't stretch a TC frame, but I have been wrong many times before...I just want you to make sure that your getting something that won't KB on you...
As far as the barrel goes, remember that if there IS what appears to be throat erosion, you can always rechamber to either 357 Max, 360 DW or 35 Remington...they all use the same diameter bullets and TC uses the same twist rate on all those chamberings.
And as far as the 22 lr goes...I would get it because they are just so much fun to shoot.