To answer that question, ask yourself if you would buy milk.com for $100 000. Probably not, I'd wager. The only reason to not sell is the hope that you might get more for it in the future.
I also wouldn't buy milk.com for $2000. Does that mean I should sell it for $2000?
In any case, there is also a time / hassle reason to not sell: It would mean the loss of the only personal email domain I've used since 1994, and that would make for a _lot_ of updating (and crossing of fingers hoping I didn't miss something important).
In any case, there is also a time / hassle reason to not sell: It would mean the loss of the only personal email domain I've used since 1994, and that would make for a _lot_ of updating (and crossing of fingers hoping I didn't miss something important).