I even tried Mom & Pop Antiques, the cool store at 3534 Georgia Ave NW, and they had one old one, but it didn't work too well. (Side note: make sure to visit them, it's a really cool little store. Lots of interesting stuff there, friendly staff and a bunch of records for sale.)
So after that, I'm pretty much out of ideas, aside from Craigslist. Any other ideas for local spots to pick up a record player? New or old would be fine, but a big old one would be especially cool.