i just saw on saltwaterfish.com, they have yellow tangs for $1.99..only 1 per order..i think they have a minimum order of $80 and you get free shipping
I had really good luck with them. Ordered some rockanemones, green ricordia (they always have for 7.99), goronians, and a couple fish. They pd shipping, everything arrived alive!
I think if you added a 2 or 3 to the tank at one time you would be okay but if you added them seperately after one has established its territory than all hell wll break loose. If your trying to do a school i wouldn't. They may all get along while they are small but as they get bigger they will fight and you will only be left with 2 or 3.