The wraps vary from $2000 to $5000
They last for as long as you keep good care of them, up to about 7 years if you really never use the boat.
If you use it hard, 2-3 years max before it will look like junk.
They do protect the boat ok, but a gouge is still a gouge. The pros sometimes get plain colored looking boats and wrap them, not the custom colored jobs, cuts down on price.