yeah it is one of the basic facts of racing that you the car at the front has probably outspent the other competitors.
Hell if I drop by targa in my 22yo skyline I have to compete against Tony Quinn who had to choose between bringing his spec-v GTR (do they even exist?), a mosler, or a carbon aston martin. Or when I head down to nsw production cars, its the same car running 0.8bar on 1/2 season old tyres against Bobby Pearson's brand new factory supplied Evo X running 1.6bar and brand new tyres every race, with the best ecu, datalogging and suspension you can buy.
Even one make racing is bullshit, people just spend more cheating than in a more open category.
In the end, if the car follows the rules, expensive or not, good luck to the person driving it. Anyone that thinks any race cateogry is some sort of level playing field is not paying attention