I would say with minimal development (aff links, adsense, some cgi) could easily go for low-mid$xxx.
2 Good, related keywods in a hot category works for me. Add to that the buzz-factor, that it's memorable and you've got a brandable site, without a doubt.
$50 seems low, but sometimes it's best to take a profit, take the money and run. I'd hold on to it, and dev or get it developped. :gn: :imho: