I just wrote my $ 460 check @ registration for this weekend's SW Division race ... That's a long way from the $ 125 entry fee for my 1st race in 1987 ( and I thought that was terrible )
Run an inflation calculation and you find that that entry SHOULD cost $250, so something else is at play here.
PART of that is that real estate (and remember for the most part we are dealing with mortgage values PRE crash when we are talking about racetracks) values are outpacing inflation, in most areas of the country, so costs to tracks are higher.
(again, thats very track to track dependent)
A great influence, in my mind, is the changing drivng environment. In 1987, dudes with fast cars got their rocks off on the backroads. Then tracks and local clubs started running 'time trials" and HPDE events. Marque clubs jumped on and pioneered this early. Porsche guys, BMW guys flocked, and may (most) of them find this outlet to be enough, no real racing is needed. And for those marque guys who want to race, many do it within their marque club.
Bottom line is a greater demand for tracktime.
More demand= higher costs.
Example, about 5 or so years ago, Lime Rock basically doubled their rates.
New England Region (or any SCCA region) pays about $70,000 in costs to run an event at LRP.
(Thats a Fri Sat event, start at 9 end at 5 day, with a max group size of 38)
So, the region has a very tough balancing act. IDEALLY they could do 8 groups of 38 each, and have a 300 entrant event. But, they must run groups that have 5 Formula cars in them. It's really impossible to fill each group. So, they are lucky to get 225 or so. That means $311 per entry to break even. (ROUGH numbers)
Now, if it rains, they lose money. One bad event can bankrupt a Region with a healthy $15K in the bank.