Read Read Read and do as much research as you can!! Google is your best friend, this website is a great place for advice but you have to do your homework first.
I have had a drilled 29G with homemade fuge and a deep sand bed for the past few years (my first SW tank). I just recently priced out a new 65 gallon setup for myself. I did it in excel and tried to be as realistic as possible. Keep in mind that I have a lot of existing equipment laying around and also in my current setup to use in the new one (pumps, power heads, plumbing parts, heaters, sand and live rock.) I am also using an old 55 gallon tank i already have as my sump and all of the lighting/plumbing is going to be DIY.
Aquarium
Dimensions
Price
65 Gallon Reef Ready
48 x 18 x 17
$289
Stand
48 x 18 x 30
$275
Shipping
$66
;">
$630
Total
Lights
Sockets/Wiring
$20
48'' Fixture
$100
Bulbs
$100
border-left: medium none;">
Sunlight Supply Dual ballast
$200
$420
Total
Reef Octopus Protein Skimmer
br />
6" Recirculating
$275
$275
Total
Sand/Live Rock
Fiji Mud
$60
style="border-top: medium none; border-left: medium none;">
Sand/live rock
$100
$160
Total
$1,485
Total
Thats all before you buy your first fishy.
Kind of hurts when you look at the final total, but well worth it in the end. It's all about baby steps...