A key question is how much you want to go to wherever it is and, once there, how much the specific tour itinerary matches what you'd do yourselves. If it's not something you'd do otherwise, it's work time pure and simple as already posted. How much is two weeks of work worth to someone who engages you for it?

If it is to a place you might want to go anyhow with activities you might mostly want to do anyhow, figure out how much you and your wife would pay for that itinerary (not your ideal itinerary, except for the remote possibility that they coincide exactly) in that place, and discount your billing rate figure by no more than half of that since it won't be a pure pleasure trip.

Finally, make sure your flights earn miles!