If anybody coming in plans to hit downtown and check out the nightlife the extended stay on 6th usually runs about $100 a night and is right in the middle of things. The Austin Motel on S. Congress is also a cool spot.
If you just want somewhere quiet to crash out near the meeting spot anywhere in round rock, georgetown, or cedar park will be decent and cheaper but its the burbs. It would probably be a nice weekend for camping too. There are several spots around Lake Travis and on Lake Austin.
I would offer couch and floor space but the wife is pregnant and wouldn't be happy about house guests.
If enough ppl will be around I'm sure a sat night meetup can be arranged too. There are several general car meets around Austin on any given Sat night but the other guys know much more about those than me.