Gong will sell you a new G10 wing for less than 200 euro, and they are superb,
That's a price thats not to bad at all, even cheaper than many windsurfer top skegs.
But I have never had a desire to make my own gear after two of us spent loads of time and cash making a windsurfing slalom board, it sailed like a pile of Poo.
Looked crappy as well.
But I do admire it when home made kit looks good like the boards that TW on here makes.