The entry fee is $20k. The bike is $20-50k. I figure costs $100-$150k for a serious privateer effort when you purchase support from an established team and I'd guess it would be double to provide your own if you have to buy a race rig. Even entry fes for your crew are $15k, I read.
Thanks to Scuderia West
for their support in the 2013 Mexican 1000