Nick, As you will see I am also in Vienna VA and know exactly what you are talking about. I have lived in the town for over 25 years and man is it changing!
It sounds like what you want to become is a wholesaler. You would get a home under contract with a small deposit and then shop it among the dozen plus builders working in town.
Now the disclaimer. I am a Realtor but I do not represent any builders. That just isn't my area of concentration. I have worked with sellers trying to decide if they should sell to a builder or put it on the open market. Those experiences, plus my observations wondering around town, led me to write a blog on my site entitled, "Is your home worth more Dead or Alive."
I looked at the what builders paid for the tear down homes sold privately and what the prices were for those that went on the open market. The numbers showed (and this was some months ago) was that sellers netted more - even after commission - with open market exposure.
More recently I am noticing a real bump in the entry level price points for liveable homes in town. With new homes commonly in the 1.3 range, folks wanting to live in the area but not in that price range are causing many basic homes to jump from the high 500s to the mid 600s.
Anyway, if you do have a connection thinking of selling and the house is need of lots of work, you may try to get it under contract and flip it to a builder.