Give us some more info on what type of build you are planning?
maby we can give some advise ?
have a look at this thread, its my first guitar i am building, bought most of the wood in the OFFCUT section at rarewoods, and the wood didn't cost me much, i just had to spend some serious time to look for the perfect pieces i needed, aldough i didn't buy the mahogany new from the warehouse, had to buy a 2m lenght, as it was the shortest one they had in stock, but you'll be able to find something in the offcut section for next to nothing. because its your first build i would not recommend spending to much money, get something basic, even glue 2 pieces together for a body, use it as a learning curve.
the price for my wood was:
Mahogany 2meters = +-R800
maple top = R120
(it was a rare goog looking piece i found to make the booked top)
Fretboard, rosewood = R50
(they sell pre cut fretboards for guitar)
Neck wood, 5 piece sapele and maple = about R150
(i bought long strips and glued them together in 5 pieces)
http://www.guitarforum.co.za/setup-mods-and-repair/manny's-first-build(in-progress)/