I can tell ya what I usually spend, your schedule will probably vary from mine though:
Gas to the show, 4wheeling and back to Harford County, Md (for one truck, assuming $2/gallon):
$50
Showfield registration (which includes 2 tickets for admission and all 3 days of the event):
$40
Hilton Hotle w/ the Mach crew (split probably 6 ways?) $161/night divided:
$25-30
Pine Grove Hotle (split again, probably 5 ways) $62/night divided:
$12-15
Admission to Rausch Creek:
$35 unless you've never been there before, then there will be a $10 registration fee on top of that

:
Food and knick knacks:
$40
So yeah, it IS expensive. Guess I average about $200 every year, more if I bring both of my trucks

This is why I start the thread SOOOOOOO far in advance, because it involves a bit of saving up- especially in these economically challenged days. Well, that and the hotels are generally booked full by February!