I just bought this tablet (used) a couple of weeks ago from ebay. I paid £180 for it, which I think is a fair price (that works out as $286, but of course prices for products in the UK are much higher than for those in the US, so I guess it a fair price would be lower for you).
As for the problems, they are associated with the transformer prime, not the transformer eepad tf101 (which is the one I have, and I assume, the one you are talking about?)
The Tf101 pretty much got unanimous praise and rave reviews, so I disagree that "a lot of people are unhappy with the asus tabs". Asus tabs are very well regarded, with the exception of the glitch that was their prime series- which was let down by gps and wi fi issues due to using different materials.
So I would say, if it's the orginial transformer, type it into google- and all the praise you will see for it should allay your fears. It really is a great tablet, so you should go for it if you get a good price