Roger Waters 'Amused To Death' - Counterfeit?

Recently, I won a bid on EBay for a Sony 180gram 'Amused To Death' vinyl lp. I was so excited. As I've seen this lp sell for anywhere from $500 - $800, I thought I very lucky to win the bid for $152. WRONG!!
After listening to the first five minutes of side A, I realized that this wasn't what I had heard when hearing this lp at a friends house. This copy, the one I bought on EBay, was horrible. Flat, mono sounding (I really think it is mono), no dimensionality...just plain bad.
Now that I've done some reading on the net, I've discovered a few discussions of counterfeit copies being sold (obviously like the copy I bought).
For future reference, is there a way to tell if a 'for sale' copy of this album is a genuine or a counterfeit?
In advance, thanks for your input.