All other things being equal, after completion of the Silver line to Reston, home prices should start to increase.,as they have in the past when Metro stations have been completed in an area. The key words in this answer are "All other things being equal", which never happens. Let me give you two examples of what else may happen.
First, interest rates, now at Depression levels, could go to 8%. That, combined with restrictive credit and appraisal standards, could knock housing prices down.
Second, the employment situation in ore area could change for the worse, due to budget conditions. For example, what if the Federal government, in an attempt to cut spending, had a 5% reduction in force? This has actually happened before, in 1949.
There are two points here. First, as long as one is both buying and selling in the same area market, it's always a good time to do either, since market conditions are the same without regard to whether you are a buyer or a seller. Second, we are in an economic state not seen since the Great Depression, and predicting market conditions two years out is something I, as a real estate agent, cannot do. The two examples of what could happen ( and, for that matter, they both could happen at the same time! ) are just some of the possibilities. I think that what you need to focus on is the overall livability of a home now, and how that home meets all of your needs. Don't overlook that there are express commuter buses that go to the East Falls Church Metro stop in the Toll Road Express Lanes from Reston right now. For more information on this and other topics, you can E-mail me at firstname.lastname@example.org.