The dot online extension doesn't have much value outside of premiums... I don't see this as anything close to a premium. That being said, it DOES work for me. The problem is you are going to need to find a buyer who is willing to work with a 2 word dot online... they are out there, but basic economics of supply and demands means that the price will be less due to less demand..
Quite honestly, I see it's most value in development. Once developed, it is much easier to get behind a domain like this...
Without development:
reseller = regfee/low $xx
enduser = mid $xx - mid $xxx (might take some work!)