Why are snow board jackets or ski jackets so expensive?

Well, inarguably, they are expensive. Some jackets have lots of special features (like North Face Jackets, for example, can have GPS thingies for when or if you get caught in an avalanche). Ski jackets use a lot of technology that keeps you dry and warm, while still allowing you to breathe. In this respect, its almost worth the price. However, skiing isn't a necessity of life (well, technically). Therefore, it is not necessary to have a ski jacket. It is because of this that companies jack up the prices: because they can. They know you need a jacket, and if you're already choosing to partake in such an expensive sport, you're going to have no choice but to buy from them. To be honest, however, I think that ski jackets are well worth the money, as they last long (I have had the same jacket for 6 years). Just a little tip here: try looking for jackets in August. You may not get the best selection, but I just got a normally near-$300 Burton jacket for about $90 at my local Ski Market during the summer. This is a great way to save money on ski-everything. EDIT: I know I said Ski jackets; i meant snow board.

mostly because of brand name. but just as important if not more, they are water/wind proof which is good when going fast down a mountain, too bad most of them are thin as paper, and dont provide much warmth. their cost of production is probably less than half of the msrp

Because they can be. The more frivolous and not-necessary an item becomes, the more expensive it is. Basically, it's so expensive because all the companies agree to make it that expensive.