I inquired about rates and here's the reply I got from buggyinsuranceguy.com in case others are interested:
" We regret that we are currently unable to offer quotes on buggies valued over $30,000. We are aggressively seeking an insurance program to accommodate these buggies and hope to be able to insure you soon"
for insurance companies to offer higher limits on coverage, they need to apply that w/ DOI (dept. of insurance) and that needs to get approved by them, which is kinda hard because the majority of sandrails/dune buggies are way under 30k. so it's kinda like trying to insure a ferrari or lambo.