Since there are a very limited amount of these NL combos in each domain. I would hold it. .coms are shifting owners again. Every year just after tax time. .net follows as people see they cannot afford the .coms Now we have .info and .mobi that are in the game. (not everyone thinks that .mobis are worth anything but with a few of the big companies starting to buy them up ... it shows promise) I suspect around July .org's will be picking up pace again but not nearly the funding available as for the .others as the rest of the market starts to slow for a few months and they see a NL .org is free. Even then I would keep it. If you can wait 5 years you may be able to buy a new car with the $$. If you get a good deal 4k + right now go for it if you need the funds.
Mid to high $x,xxx — You might want to put it up for auction. Might go for $xx,xxx if it'll be well-developed.