Agreed. If there is a bike coop where OP lives, he could find a high quality used bike within his budget and have it assembled for a nominal charge.

Otherwise, BD is the way to go and as I said, for a basic build, he's out $50 - unless he wants to upgrade the bar, shifters and saddle, in which case it would be more expensive. The reason why most of us pay a qualified bike mechanic to do the work is to get it done correctly and save ourselves time doing something we'd rather spend doing something else.