Sucks, but at least you're ok. I feel your pain. Had an off in my 235 on track last year in the pissing rain at a spot where a westfield had gone up in flames two laps prior. Same conditions and driving all day. Outlap was fine, must have hit oil on water second time round, rear snapped out, couldn't catch it and could only do my best to scrub off speed before the tyre wall. No structural damage to mine, but needed new front bumper, new bonnet, new passenger side fender, new intercooler and reskin of passenger side door. Would have been far less if the tyres hadn't collapsed onto my bonnet.
Luckily had track insurance. Total cost to repair: £8k. Bear in mind mine was cosmetic, it'll sharp ramp up with any structural/ major component (diff) damage but it'll give you a UK based idea.