What were your biggest purchase mistakes?

[fishoholic]

Originally Posted by kien

I purchased a 150g tank a couple of years go. Now I'm out thousands if not tens of thousands of dollars! What a money pit!

Couldn't agree more! Only mine's a 230g tank

[Madreefer]

Years ago I bought a Seaclone 150 Protein Skimmer for only $300. The store I got it from has since drastically dropped the price to $200 for a quick blowout. It took me a while to get rid of this highly recommended peice of equipment free for the taking.