You can spend as much or as little in IT as you want. Really.
I dropped alot of cash (in ITC terms) actually building my old car, but the result was a car that was super easy on equipment and could win on any given day.
Tire budget - One per weekend, including running enduros.
Front brake pads - 2 sets a year
Rear shoes - One set every 2 years
Front hubs - One set a year
etc....
But it wasn't a "cool" car. 90 world blistering HP and the worlds most widely spaced 2-3 upshift.
You can race "cheap" (in racing terms) and win, but you have to surrender some cool points.
So... $5000 to $7500 can get you an ARRC win in ITC... Maybe.
But that AIN'T EVER gonna happen in ITA. Not unless the first dozen or more cars all crash or break.
So if you wanna race cheap and be competitive, pick the right car. But DON'T pick ITS or ITA and then complain that you are being outspent (note: not singling out anyone in particular, I'm just sick of guys standing in front of their ITS BMWs complaining about what they have to spend on tires... SHUT UP!!!)
And this NASA PT thing???
Good luck with that. I see about a dozen holes in it. But they won't matter until if/when the classes get popular. Then there will be a big mess. Especially at something like a national championship.
And just for the heck of it, I figured up what I spend to build and operate my old ITC car vs. what it would cost me to build and competitively operate that "old" Neon ACR in the driveway for SSC.
The ITC car is cheaper by my math. Build costs are pretty close (once you factor in rebuilding the motor and shocks and tranny in that 150K mile Neon it isn't much different than building a good ITB/C car) but the C car murders the Neon on consumables, especially tires.
There are alot of "myths" in club racing. That Showroom Stock is "cheap" ranks almost as high as spec Toyos saving money.
FWIW