" For everybody that thinks $1800 is expensive for a foil, consider this. Knowing what I know now, and having the amount of fun I've had, I would pay $18,000 if needed. I haven't felt this excited and youthfully energized since my early days of windsurfing. To me, that feeling is literally priceless."
Dave KalamaProfessional Waterman

Consider also reading a lot of tutorials and being overly cautious for your first steps. A lot have been said of the dangers of learning to foil, but it should be stressed that mistakes can break the foil very easily. Just read yesterday that a beginner just broke his foil on his first session in the basque country, the foil is totalled, both mast and wing is broken.
The forces on it are huge, in even the smallest of whitewater.
Some investment in caution will save you a lot of money...