Figure about $60 to $75 for a coral catshark and $125 to $200 for an epaulette shark.
Flying fish express, the marine center, jeff's exotic fish, saltwaterfish.com, premium aquatics and just about every other online place guarentees live arrival. FFE guarentees 5 days after arriving it will still be alive unless it is a restricted species which these aren't.
Look around. Just remember you will have to add between $50 and $75 to the price just to cover shipping. For an epaulette it may be worth it ( I have seen them for up to $500 in some stores) but a LFS should be able to get a coral catshark for a decent price. The LFS by me gets coral cats in for $75 to $90 depending upon the size.