I think it really depends on how patient you are.
If you want a bike now, you'll likely have to settle for one of the standard offerings from Bianchi, Fuji, KHS, etc. Those bikes are alright (I actually really like the Flite 100 for urban assault purposes), but you have to realize that to get the price for them down that low, concessions are made with the components. They're just not built to last and you'll likely be replacing your wheelset or drivetrain within a year or so.
That being said, maybe this sort of upgrade plan would fit perfectly with your budget. If you want to get on the road as soon as possible and are fine with upgrading parts on your frame in the future, by all means get out there and test ride these bikes. Some of the 2006 models are already available in stores, so you can likely find a bike that not everyone is riding ... (yet). On a side note, powder coating is cheap.
If you've got more time, keep an eye out for used options. Craigslist might be a better option than Ebay depending on where you live. Web forums are also a great option. There's always someone moving up to a better bike, so you can likely find something in your price range that's had some nice upgrades done to it. That would probably be the best case scenario for you, actually. You could get a bike that's in your price range, but hopefully someone will have already replaced the troublesome parts.
If your budget is strained and you're really patient, maybe you could work on a road bike conversion. This can take a huge amount of time, but if you rebuild it from the ground up it can be an awesome custom bike. Not a track bike, but do you care?
Anyway, good luck!
$0.02 ...
- eyefloater