Hey Dan,
Agree 100% with them being hit or miss, also if you have the ability to see one at a local store you would want to see that it is at least eating mysis, its very easy to get them started on this. If, like me, you dont have much access to a local store, you may have to go with ordering online. I would go through Drs Foster and Smith(Liveaquaria.com), mainly because they offer a 14day guarantee. You've got two choices, order one hope it lives or do what I did, order 2 or 3 and hope one lives, I know that sounds bad but its not easy to get one that will do well. If you do go the route of getting more than one, you'll need to keep them seperated as they will fight and this will certainly not help their chances. If they arent going to make it, it will most likely happen in the first few days, which sucks, but you can at least get a refund on your purchase price, keep in mind that you cannot get a refund on the shipping which is why I went with more than one. If they make it through the first couple weeks and you get them eating mysis, you should be good to go. I am assuming you have some aiptasia in your tank you are trying to get rid of? It would actually be the best if you did as they are going to go after those much faster than any food you give them, you need something to help get them started. If you get really lucky and more than one makes it, I dont think you'd have much problem finding someone to take it. That is just my $.02. Good luck, they are cool fish and will rid your tank of aiptasia, but they are not an easy fish to care for.
Allen