My first roadie was a Scattante with Ultegra that I got for $1k. The frame was probably very similar to either of those. The ride was stiff, but I made my way up to Cat 2 and did well in a few Pro/1/2 races.
You do get what you pay for, and there were some shortcomings with the bike I had (wheels, tires, rim strips), but I lived.
Honestly, it's probably a decent frame, might be a bit stiff, but that's aluminum. If it's a good deal, and you go over it once you get it, might be worth it for you.
You're not going to get the same support as if you bought through a shop, but then again you won't pay as much either...
Also, I have NO IDEA how they're selling a complete Dura Ace bike for that much and making money. Must have super-low overhead.
Edit: Ok, so Cane Creek brakes, KMC chain and an Ultegra cassette do help a lot.