If you think there's use for colothis.com then you could charge it as high as you want. But note this, how common is colo this used in server colocations? The more common the words then more people will type into the search engines. That leads to possible hits to that particular Website, which worth more that way.
However, if you register your domain name for the sole of branding and lack type-ins and link popularities then you could try developing it. Make it into a Website, that serves as a message board, chatroom, selling goods, and etc... That's another way of increasing the value of your domain name.
Base on those criterias, colothis.com doesn't worth much at all. It should worth whatever price you register the name as.