man i've been kiteboarding for 5 years. when i'm travelling in the carib where theres consistant trade winds, its the best sport in the world. when i come home and kite in ontario it just pisses me off 90% of the time - usually for no wind, bad wind, or not enough wind. i just replaced my lightwind kite with a 1996 supersport nautique instead.
unless you live somewhere thats a hotspot for the sport like hatterass, corpus christie, or the gorge, you'll get let down alot. make sure you have a ton of patience. keep your costs low. just borrow a trainer kite for a couple of days. after you learn it, you'll never use the damn thing again.
hope my cynical opinion helps.