I do live in VA but not NOVA so I can't give you specifics but I did find a local university with a psychological services center that offered low cost testing (it was done by graduate students). Maybe you could find something similar up there? It cost us $250 for a full battery assessment including WISC-IV and WJ-III.

Mom to 2 kiddos - DS 9 with SPD and visual processing issues and DD 6 who is NT