Thats some cool shit, always wanted a fish tank, friend bought one and I was jealous. Like you and otehrs have stated thou, salt water is super hard, its more a lifestyle then a hobby I guess. I would like to have salt water just for getting some lil lil tiny spinless jellyfish or octopi. But fresh to start sounds best.
If one were to start from scartch, what would you say for a 100 gallon tank would be a good amount to put aside for investment in fishys.