I would scour craigslist. I'm also from seattle, and there's plenty of choices. Just set the category to "bicycle" and type in track bike or fixed gear
I wouldn't buy the first thing you see at your lbs. Velo bike shop is great in seattle, they have a bunch of track bikes. There's also a track specific store in ballard. Seattle is full of "fixies".
800-1000 will get you a complete entry level bike, and I recommend getting a complete. Best bang for your buck, you should swap out things that fit you personally (stem, saddle, pedals), and upgrade as needed.
As far as specific models go: Fuji Track Pro, Trek t1, Felt tk3, Motobecane track (great deal for a beginning trackie, duraace!), cannondale capo are all beginning alu frames. Because I don't know much about your situation (experience, fit, what you're looking for) I think that's the most I can help with right now.