Personally I think this domain is better suited for actual mugs. I could image it as the name of "THE" online mug store. Maybe offering a wide variety, funny/sarcastic slogans... and then some higher end stuff...
Lots of potential for someone in the mug business or willing to put in the time. It would be about finding a buyer who saw that value.
Personally I wouldn't part with it for less than $1,000.