can't go wrong with mushrooms, especially if you learn how to propagate them into many or just scatter them around your tank. i paid 20 bucks for a rock with 17 shrooms and now i have about 25 or so. most were small when i got them, but they are quickly getting bigger. just make sure next time to get a different kind so you can have some variety. one thing about shrooms is that you really don't have to worry about losing your money, because they are the hardiest corals in my opinion. <a href="http://www.garf.org" target="_blank">www.garf.org</a> has some good info on propagating corals, you should check it out.