Buying a rebuilt engine off of Ebay ?

Hi everyone! About a month ago I bought an RX8 which I knew had bad compression. It turns out the 2nd rotor's apex seals went out. I pulled the engine from the car and opened it up to find that I would need to replace the rotor, the housing, and the iron back plate in the second rotor. on top of that I would obviously have to buy all the seals for the rest of the engine. To rebuild the engine myself would cost roughly $2,250. I found a company on ebay that rebuilds the whole block for $2,500. It comes with a 1 year 12K warranty. I guess what I am getting at is which is the better option to go for? If anyone knows of someone that does great rebuilds please let me know. I'm not going to Mazda for this due to the previous owner having them rebuild the engine and it's now dead with only 30,000 miles on it!

Here is the Ebay listing:
Mazda RX8 Engine 1YR 12K Warranty 6 Port or 4 Port Available | eBay

Thanks,
~zattack906

Buying a rebuilt engine off of Ebay ?