Loudoun Co. is a fine place to call home.
So is Fairfax, but you have to have a solid 6 figure income to afford a decent single family home.
Relatives are looking to buy in the area. $500,000 gets you a 3 BR home, maybe 50-60 years old, decent condition, not always with a basement, maybe a one car garage, on a 1/4 acre lot.
Even during the housing collapse, homes there held their value fairly well compared to the rest of the country.