Hi Kate,
Just in case you dont know: you have a gem (though the .us does hurt a lot).
Are you aware of last purchase by Chris Chena? He is probably the biggest spanish domainer (actually from Paraguay) and he has sold a bunch of top generics including juegos.com (spanish for "games") to buy
clasificados.com.
The price has not been made public (not that I know) but this was for sure in the $xxx,xxx range. Im not saying yours has even a closer value BUT you can get an idea of how huge your keyword is.
My advice: Develop!!