1) think electrical and water bill
2) think water change, di unit, resins, carbon, salt...
3) think buying corals (how many, how much)
4) think "what ifs" power failure, overseas assignment, holidays...
5) think supplements, additivies, medication (if any), frag plug, gel glue, etc...
6) think stay up late just to hustle and bustle for chiong shipment
7) think buying fish (how many, how much)
8) think fish got ich how? Tank outbreak with cyano how?
9) think cost of equipment, sand, live rocks
10) think if you do not reef, and channel all your potential monthly expenditure into buying a monthly unit trust. You can easily afford another new house in 20years time! (for some, it could be in half the time).
Oh well, actually just 2 questions...
1) got spare time?
2) got spare cash?
Maybe a 3rd one, got a supportive other half??
If you do, it's half the battle won.