Well I research all the fish pretty heavily and then right down on paper my long term goals for each of my tanks. Planning, because many of my fish are growouts etc. I do have a terrible problem buying though. I have a good job now where I make quite a bit of money, so at times I act like a spoiled brat. I think hell I work hard for my money I deserve it so I buy the fish. Then I get more tanks. It seems like a never ending cycle for me. Heck I have just now started adding tanks to my garage. It gets a bit rediculous when your fish room is running out of space, so you start moving tanks to the garage. I did the math the other night and I have already spent $5000 on this hobby over the last year. Thats not alot for me, but hell money is money.