Interesting name, especially for me. I have 'Video Gamer's Zone' (dot com). Actually, I have the non-plural Gamer version, as well. I always wanted to develop it. I would need to take a few more programming classes, but I have already signed-up for them and bought the books. If I could only take a little time off to get them accomplished, I could probably get that done.
Anyways, there is all kinds of an upside if you develop it. As it is, it is a very good premium name, especially because its descriptive, a well trod niche, and etc. But kite26 is right, you need the non-plural version to redirect the lost traffic, or you will frustrate a lot of users that don't naturally use bookmarks to navigate the web.
I would say it's worth $500.00 to $600.00 as a name if you have interest. If not, $450.00 minimum. But if you developed it into a game site, even just a cheat codes blog, I am sure you could get upwards of $1200.00 and up depending on how well you do it.