A few months back, I decided without really investigating, that it would probably be cheaper to go to TPC than YAPC. After all, I live in Southern California, and it's about an hour or two down to San Diego. St. Louis I'd have to fly to.
But even with early-bird registration, driving to TPC ends up costing more than flying to YAPC! And if I get a hotel room (don't want to go crazy driving back and forth every day) the total ends up about double. I suppose if I had a company standing behind me, willing to foot the bill and grant me time off, I wouldn't even think about the cost -- but out-of-pocket it gets pretty ouchy.
Sadly, I realized all this this weekend, and it's too late to plan a last-minute trip to YAPC. So I guess I'll have to wait for next year. Darn.