I suspect that those sweaters are very fine, but keep in mind that some people are willing to pay more for a particular design. "quality" isn't the only important criteria.
There is always someone who can custom make the same type of thing better for less. Its really not about quality, cut, finish, materials, its about that little label they add when they are all done. That is what raises the price 300%
Yes Otavalo, the city famous for their wool and wool products. There is a gentleman who sells direct from Otavalo on ebay, but if you buy 3 or more sweaters he will have them custom made in the style, color, and measurements you wish. At least he did that for me. They will last forever.