If you're talking about building a glass laminated longbow, you're pretty much in the ball park on price of materials. But you have to add in the cost of making the form and the hot box. That pretty much doubles the investment.
But the good thing is, you can use the form and box over and over and over to build many more longbows. One of the guys in our club made a form and, at last count, some 45-50 bows have been made on it. Most all oftheclub members have used it.I did.
edit... Where to buy. You can get everything from Bingham Projects
http://www.binghamprojects.com/product.htmor you can shop around the internet.The Woodshed is a source for good wood.
http://www.tradstore.com/woodshed3 Rivers has some glass laminates.
http://www.3riversarchery.com/
I know there are more outfits to get supplies from, but I lost a lot of my bookmarks and haven't gotten them all back. [X(]