I’ve been thinking about this same subject so I decided to call DAN today. Membership is $35, plus Standard coverage $25 (chamber, but no ear trauma), Medium coverage $35 (most all coverage), High coverage $70 (everything). It turns out that my personal health insurance does cover hyperbaric chamber treatments, evacs, and ear trauma. You should check your own insurance to see if you are covered. I might still add Dan as gap coverage in case my insurance limits are exceeded. Plus Dan offers trip insurance.
Equipment insurance is covered through a separate company. The rates for that are $3.50 per $100 of coverage. So my $4,000 camera & housing alone will cost me $140 per year to cover. For that amount I’m going to just keep a close eye on it. I bought my dslr camera at Best Buy with the $150 extra for 4 years of no-fault insurance to cover my camera in case of flood. If it floods I get a new camera. I’ll baby my housing and strobes in a pelican case. Just not covered for theft or lost. I will carry my rig onto the plane.
Hope this helps.