EcoTaxi in use quite a bit mainly with .com and a location tacked into the name (a few country code too). It only sold once and not for long, but that was a long time ago and I think it is a term much more relevant now. I like the name if you can convince one of the existing places to upgrade to the .co. The .com is in use in South America, the .net goes to a site but not information, and the .org is for sale. I think there could be a window for selling it in .co, possibly.
I like the sound of PrintBox, but do not know what situation is re the status of name. I see that both the .com and .net are in active use with services.
I do not know the .co ecosystem well enough to suggest a price. Good luck with them.