Personally I'd buy it from an Authorized Alpine Vendor, not eBay. They will not support your warranty or anything that happens if they are not an authorized vendor. In all my years in Car Audio, just say no to eBay or unauthorized vendors. The only Online Authorized Vendor to my knowledge is Crutchfield other than Best Buy, Tweeter, and Circuit City.
Thats a pretty good price on the Type-R, but as mentioned, you will not have any warranty on the item from ebay.
As Ken mentioned, Alpine only authorizes the companies he listed for online sales.
As for how it compares against the e3.12, formally known as the 13Kv.2. The Type R should ideally get louder depending on power input, but sound quality and low frequency extension should go to the e3.12. Plus its $100 shipped with warranty.
The e3.12's also will not be shipping until around mid- january.
Either way, I dont think you will go wrong, but it really comes down to your goals, power and box that you are going to use.