What would be a fair price for my site?

I do some brokering on the side of internet only sites. Through bizbuysell the average sales price has been around 1.5-2x net 12 month net. The multiple has fallen dramatically from 2006-2008. If you aren't doing a lot for the site, I would just keep it. You are going to get clobbered on taxes most likely, as cap gains has gone up for 2010.
 


Normally for adsense related sites you can demand anything up to 3 years rev if you have about the same length of track record earnings and stats. Normally, 24 months seems to be the suggested norm, but anything is possible - as someone said, if it is a competitor you should shoot for the stars.
 
It seems you have a good enough site, you are earning good. Don't even think of selling it, That is my view. Otherwise in the future you will repent.