It's not worth the time and effort to try and piece together a budget AR these days given the prices of entry level rifles from established AR manufacturers like DPMS, Bushmaster, S&W, etc. Not to mention Norinco. Unless you get really lucky or can source the majority of parts from a single seller/vendor multiple shipping charges will kill your budget. Having to purchase the required tools will also have to be factored into the equation. Even then, you're left with a frankenrifle that has little resale value, whereas a factory named rifle will still retain much of its value and will be far more salable. However, if you're very patient and snap up key EE deals the moment they are posted you can build a high end AR for a third the cost of a factory rifle from a top tier manufacturer.