There is no "google tablet", at least not yet. Google has their own brand of phones "nexus ..." which are manufactured by HTC, but as far as I know, they have never manufactured tablets. Any android tablet will be branded by some other company, and there are a bunch of 7in 2.3 tablets.
Do you have a link or picture to the one you're looking at in particular?
For $85, it's probably worth it. Depending on the specs though you may be limited as to what it can handle and being version 2.3 you're missing out on some of the new android goodness.
One big problem with that tablet is the resistive touch screen. This means it won't detect your finger just by touch, you'll need to actually press into the screen. You would normally use a stylus for a resistive screen.
You can google resistive vs capacitive touchscreen for more info