Tube Testers. Which to buy and where?

I'm hoping I can afford a tube tester, used. I'd love to be able to test output and input tubes, 6550, KT88, EL34, etc.
I've no idea how much they go for. I've looked on A-gon here, but I've no idea if these are worth pursuing or junk.
I'd even consider new if new could be had for a few hundred, or preferably much less. Then again, I'm thinking if they were that cheep, maybe everyone would want them?

Any input is appreciated.
TV-7 and have it calibrated by Dan Nelson in Arizona. I've had Hickoks and the TV-7's (I've had a couple of them) are my favorite. You might want to check EPay (EBay), but they don't run cheap anymore. Couple of hundred to about $1,400+ within the last two months.
Thanks Mae.
A couple of hundred to $1,400 plus is quite a range. I'll look.

any thoughts on the B&K tube testers?
The B&K 747 is a solid state unit that is easy to use and tests all the later tubes (50s on up). They can be found for $300 or less depending on condition.
Anybody know anything about a unit labled NRI Professional?

I bought it lately at an antique mall.

I have a B&K 650 Dynaquick out in the garage. I used to use it to test 6550 and small signal tubes but have no more tube equipment. It did a good job. matching sections of dual triodes such as 12AX7 etc.I would love to have it out of the garage.
I think the TV-7s are cool looking. I used to see a lot on Ebay.

I bought a simple to use B&K Dynajet 606 on Ebay last year for $50. It has served me well.

I'm looking for a tube testor as well. Especially for 12AX's and 12AU's. I'll help you get it out of your garage. What do you want for it?