Back in October or November when they released the entry fees and classes, they also posted this on the registration page:
Please note: Online registration is currently for race entry fees only. We will be sharing information regarding required USAC Insurance, IRC Tracking, Tech fees, garage location requests and optional tent rentals for KOH Week in the coming weeks.
Yes, those extra costs are expensive, but the potential benefit is huge. If you crash, get hurt, and need to be helicoptered out? IRC knows you crashed, they call you on what amounts to a satellite phone built into the unit, and they know your exact location. And then will the bill comes due? USAC covers it. Or if the worst happens, and you accidentally hit a non racer who was just lost and crossing the course in the dust? USAC is there in case of any lawsuits.
Well worth $435($250+$85+$100). Hell, if you break down outside of radio range? The only way your crew will find you is by checking IRC tracking. Not to mention, it gives your sponsors the ability to track you live on the internet.
The more I think about it, the more I realize that racing without those things is just asking for trouble. Would I prefer if those costs were cheaper? Absolutely.