While all the above is true, in my limited experience, cost wise I think you would be better off buying the whole rifle from one of the dealers on the board then eating the $20.00-$30.00 bucks to have your local dealer FFL transfer it to you.
I think you can bring the cost down further by buying a separate complete upper and lower, have the upper shipped to you, and the lower to the FFL for transfer.
I did this recently, bought from the local dealer in part to say thanks for the help he provided, and to support the local shop, even though it was a bit more. On my second AR, I just bought separate RRA complete uppers and lowers for about $150 less than the origial Bushy.
Hope that helps.