I go to most of the SCCA Brooksville Event days. You usually get lots of runs because so few people show. We only got five runs this past event because of rain, but it's usually along the lines of a dozen or so.
If you want more runs than you or your car can tolerate, you should go to SCCA practice and/or events. Also, if you want to autocross with guys who are very very fast, you should run with SCCA. There are usually at least a few of them who are on hand.
Also it wasn't mentioned that if you attend a SCCA event with your $40 fee, you get $15 off of your $75 SCCA membership. That makes SCCA membership $60, then your autox events will only cost $25. Going out for lunch doesn't seem like a big problem to me.
For me, though, the biggest thing FAST has over SCCA is classing. We are a small population region. We don't get 200 drivers per event like .. say .. Washington DC Metro area. The FAST classes are great for our area. I agree with Muddy about the competition that arises because of this. Any club that allows race tires to run against street tires has a problem. Additionally allowing race tires in a STOCK class is equally retarded.