Don't look on eBay
Their price is not too bad IMHO. If I buy the parts myself I get the same price.
All miners sell on eBay for profit. It's just a sad fact. They regard eBay buyers as idiots. If you buy from eBay you are virtually guaranteed to never make a profit from mining.
No one regards ebay buyers as idiots. It takes time and know how to build those rigs. Thats like saying car makers think all of their customers are idiots for not being able to build their own cars. Im pretty sure its a little early to make calls like that. I bought a litecoin mining rig in april for about 1300 and I mined about 400 litecoins with it, and its still going for other scrypt coins. With the price of litecoins at 40 dollars at one point, that was about 16k...so I dont know how youre doing your math. More coins are made everyday and anoncoin seems to be the most profitable scrypt right now.
I know lots of miners that dump their mining equipment after a few months on eBay for more than they paid for it, knowing full well the rig will make a loss, and people only buy on eBay because they have no idea how to do ROI calculations.