Tube Tester Option

With all the money I "gamble" on audio, maybe I should just buy this and try it.  
It looks like it only tests small octal tubes, and it doesn't say what is tested--transconductance, emission, noise?  These small tubes are the type I would just have spares and I would "test" the tube by occasionally swapping in the spares to see if the sound improves.

I do own a tube tester, which I have lent to a friend who has more uses for it, but, it is quite a bit more expensive than the model you show (it is an Amplitrex), and can test many tube types, including those with grid caps like the tubes I run.
Larryi, I'm most interested in testing small octals so it may work for me. You are right--it's not clear what it does test exactly.  I wish someone had one who could review it. 
I own one of these little testers..  Work quite well. They have a power valve tester also. It does singles.

I have a Multi Miser that I love for power valves. It will do 4 at a time. 

I have a Hickok 539, what a complicated piece.. Maintenance is always an issue and accuracy, is at best within 10-15%.
You have to really pay attention to analog stick meters.. They are not known for accuracy UNLES YOU keep them that way.. ACCURATE

Good investment...
If you don't live near a dealer who can test tubes for you a tube tester is not a bad investment. That one looks interesting but a bit limited perhaps look into what else is out there?
will this simple unit also test your tubes?

I advise anyone having tube preamp, amp, tuner, phono to get a simple tube tester.

that one looks nice, I want more variety of tube types
@gndrbob,  I wouldn't think Atmasphere would have tried this product as it's clearly for hobbyist use.  I would think he has a legitimate Hickok or something commercial and substantial.  

I just need something to test my 9 pin preamp tubes.  I have a ton of 12au7 variants that I want to sell as I no longer need them.  I'd like to be able to make an accurate representation about their condition.  And yes, I realize that absent something like TubeZilla at Upscale, nothing is guaranteed accurate and calibrated. 
@jbhiller ,
I know, but he would be the best person to ask if it is worth buying.
Why spend $130 when another $100 or so would buy something that can do the job without question.