As a follow up, here are the co's I found via a quick search with rates base on a claimed value of $30,000. Locktonaffinity's policy covers multi days events for the price listed, the other co isn't stated.
http://hpdeins.locktonaffinity.com/
Single-event policy: $198
6-event policy: $996
9-event policy: $1222
12-event policy: $1416
15-event policy: $1580
deductible 10% of stated value or min 2,000 to max of 5,000
http://www.ontrackinsurance.com/index.aspx
single event $178.00, (they offer a $5.00 discount for club members, this was not reflected in the quote)
deductible is 5% with a $1500