Quiknot, that is one sweet revolver you got there. The -2s are highly prized because they were the last 29s to have pinned barrels and recessed cylinders.
I think $500 for a nice one is low; N-frames prices have risen tremendously in the last couple of years.
Barrel length and grips affect value too. For instance, coke bottle grips alone are worth over $300, and they are seen on some 29-2s!
Check the online auction sites for completed auctions to get a good idea of current value.
How about a pic?