namewaiter said:
nice name ... id say low $,$$$ - mid $,$$$ for the right end user
I'll have to second that, only with the possibility of going higher with the right bidders seeing it. Of course, open247.com is the absolute strongest for biz use as it's the most versatile (can mean buy, sell, trade, dine, help, service, absolutely anything), and is consequently about the most valuable 247 name out there.
Sell247.com is right in there with the list of second-spot 247 names, though, so still very high value. It at least INFERS being open 247, so ideal for any online sales site especially. You could probably sell very quickly for med x,xxx; but I'd let the bidders go at it for at least 2 months and see just where it climbs to. I think this name is XXXXXXtra strong for an online sales site, and I think you will get huge values in the bidding, much higher than we are appraising.
Greatdomains.com would take this, if you haven't put it there already. sedo would place it in their best names area. You asked where to best sell it, so here are a couple:
www.sedo.com = the most well-known site for buying/trading/selling/auctioning domain names. Names listed for free, and they will help with negotiations if you want. You'll get the most experts and end-users checking this out. Top recommendation.
www.greatdomains.com = very well known. Free listing of your name for sale. They ONLY take quality names, and have a variety of prerequisites, but yours will meet them all. They will contact you by phone with details, how to best value your name, and will assist in the sale negotiating if you like.
Be sure to ask both about any fees; for example, they do charge fees to negotiate with buyers for you, and will take a cut of the final sale. But it's worth it, for the exposure they will give you to the widest variety of buyers worldwide.
Good luck. Lucky mongrel.