[mudman]

Go to a local HD with a sketch and measurements and they will give you an est. on lumber and can help in the design of the structure. If you are going to construct yourself (I highly recommend this, the deck contractors around here are the ones that couldn't cut it building houses) then go to your local library and check out one of the fifteen books the have on deck building and gen construction, read a little to get a feel if you can do it. Figure buying/renting tools you don't have, delivery, scheduling, financing, etc. If you are not a moron and value fit and finish (and can plan a project like this) then do it!
-Jeremy