Tube testers for 6922, 12ax7, etc, etc,

Looking for some advise with tube testers for 6922 and 12ax7 tubes. I'd like to buy one but don't have a clue as to which kind to buy, I see many types on ebay for resonable prices. I hear they need to be calbrated every so often. The concerne I have is buying one off ebay and getting some one's flea market special! I guess I'd like a tester that test for shorts, gases, mutual conductance, etc, etc. I would like to spend around $200 for a simple to use tester. Can this be done or am I spinning my wheels here and need to spend way more? Do any of you know a source for testers? Thanks in advance.
A B&K 747 is a good tester for the money. I beleive it's based on Hickock's expired patents. The good thing is that it's very easy to calibrate and does all the test you mention. The 707 is the tube version of this tester. These are on Ebay all the time.
Look for a BK DYNAJET 747. It is ther very latest model and should be in pretty good shape if you can find one.
>>"I would like to spend around $200 for a simple to use tester."<<

Sometimes you can pick up a B&K 707 for around $200 on Ebay.

Also the B&K 606 is a nice little tube tester. Easy to use and you can calibrate it yourself. You can pick one up on Ebay for around $65.00 plus shipping.
Thanks guys for the info, I have been doing some searching over at AA and many say don't buy off ebay as there most likely needing calibration and internal parts, is this true? If I were to buy one and it needed work who does repairs and calibrations?