It's worth diving at least once and you'll want to do at least 3 or 4 dives despite the cost. The deeper dives are the more interesting ones, more formations and structures to check out. The clarity of the water is amazing, remember one dive where there are old tire tracks on the bottom and you'd swear that you weren't under water seeing them. Have dove the mine twice and have thought about going back again, the cost does put me off though. Do look for lodging elsewhere, their prices are too high. Exposure suit wise a good 7mm wet suit will keep you comfortable, though a dry suit will be better for the SI. Be prepared to be tested and baby sat a bit, the first dive is a shallow checkout dive, they will check your buoyancy and probably make you buddy breath off your primary. Also if you plan to go back be sure to have your log book stamped! They are serious about checking log books for prior dives in the mine and if you don't have the stamps you'll get stuck doing the shallow dives again.
