Ok here is another option....Georgetown Studios and Engine Room. I looked at it for a work event. It is the old Rainier brewery room. It is really a cool venue and it's $750 for the venue and it let you bring your own caterer in.....and it has PLENTY of parking.
How many peeps do you plan on inviting? You could probably pull off a Trader Joes spread. Buy all the wine, beer, sparkling water, apps, cheese, crackers etc for about $500 - $700. Depending on what kind of vibe and how many you are inviting. Have some high standup cocktail tables and for the dj, put an awesome playlist together and use that as the dj.
Anyhoo I hope you find the best place possible.