LOL, I bought a rock with about 12 "rare red Tonga mushrooms" on it from a store in Victoria for $90. They melted off the rock within a couple of days and I had a lovely paperweight.
I also did the buy one get one free fish from petcetera, "wow if I buy two I get two free". Yeah, putting four fish at once into a 20 gal....not so smrt. After that my next purchase was The Conscientious Marine Aquarist by Fenner and I had some reading to do