You can find various AR-15s at different prices. But making your weapon is different from buying it. Weapon Building, as you see it, is quite tricky. It requires patience, which is low, in fact, for most of us.
When you decide to build the weapon by yourself, you have to be honest. The AR-15 is a beautiful gun that can be personalized to any level. Many parts and accessories are considered too expensive, but you can get these for affordable prices.