Roger, you hit the nail on the head about whether you offer money or not. Karting is a hobby, not a profession, for most of the drivers (at least everyone that I know). This is regardless of how they want to twist it, whether they pay a big team to be under their tent, dress in their best suits, have manufacturers stickers on their karts and team suits on, if they are not making a living (paying mortgage, food, college, etc. and are in college or going to work on Monday) from their earnings as a karter, they are a hobbyist, plain and simple. They are not a professional, even if they are home schooled and travel all over the country racing full time, at the track every weekend, want to be in F1, does not matter, they are not a professional karter.
In fact, the fact that you are now attracting the solo drivers versus the big team can be a plus for the future of the RIGP. In the days of SKUSA Midwest under Mr. Janowski, it was still a lot of solo drivers even though it was called a “Pro Tour”. The word “Pro” should be removed from literally every karting event, even Modesto!
The difference in the Midwest now, versus then, is that now many of the shifter guys from that era are either out of the sport or are now doing road racing. In those days, the SKUSA Midwest was primarily a sprint series (South Bend, Portage, Commercial Point, Norway, etc.), so RIGP fell right in line with that. Had SKUSA in the Midwest not died out, RIGP would have been huge with solo drivers at least in the shifter classes as it could have been a stop on their schedule.
Roger, I would say hang in there and look at possibly not paying money or reducing the prize, since it does not make that much difference to most karters (hobbyists), focus on the solo guys and see if you can attract racers from Badger, Norway, CES, etc. to try it out. This would provide a solid base from the Midwest rather than worrying about attracting these “professionals”.