They are like snowboard pants, and I have sailed a lot in my snowboard pants. One difference is that the cuffs aren't so huge because you don't need to fit them over snowboard boots. I do trip on my snowboard pants pretty easily when I'm wearing them with normal or sailing shoes.
The pricing isn't that different, so if you don't already have snowboard pants I'm not sure that you'll find those for much cheaper than sailing pants.
I have snowboard pants, yay! But yeah, it looks like for the price, you mise well get proper sailing gear. not everyone has a closet full of North Face, and I was looking at foul weather gear. You can get it pretty cheap online at least.