going to build my first ar-15, well the bottom half anyway. looking at a yankee hill machine upper at riflebroker.com. their $200 less than any other company i found. $689 for a complete upper w/bcg and charging handle.call me alittle sceptical but it sounds to good to be true. most other companies are out of stock. rifle broker says they have them on here. thanks in advance for any imfromation.