The prices seem a bit high in my opinion. Maybe contact some of the cottage vendors here and see if they can custom a 15x15 for a better price. The Cooke stuff looks top notch but that price seems a bit high.
you can get a 16 foot Kelty noah for $75 also. Tons of tie outs and extremely well made. They are heavy but if you have the space in your canoe it's something to consider.