I used to think that way also.... When you have the time, tools, material and know-how it's pretty easy to look at something and think it's WAY over priced. Build it yourself and see that you can make something similar to it and look just as good, in your spare time after your day job that pays for all your toys. Now, imagine doing that for a living and paying for a shop, employee's, tools of much larger proportion, all the "little" expenses that come with running a business, and you'll find that the price to design, test and mass produce these items is a lot more than what we can make them for in our own little hobby shops.
Personally, I take a lot more pride in something that I build rather than buy, but when it comes down to needing it now it's really nice to have these products out there on the market to choose from and when you put a price on your time you will see they are not priced out of line.