We’ve received a strong offer on the house and the buyer wants the piano. Moving the piano might be a moot issue.
Sounds like it can be a win-win! Congratulations!
My mother moved from MI to AZ last year. She sold her piano in MI and bought a new one in AZ. If the piano is not extremely valuable or a sentimental piece, this could be a good option. Selling to the piano to the home buyer sounds like the best solution to me.
1500 is a great price if professional piano movers. Last time I checked to move a baby grand cross country by professionals, who also insure and control the climate of the truck, the cost was $2500.
Yes, go with pros! I joke that the reason I married my husband was that he had inherited a 1917 6’-4" Steinway from his piano teacher. She bought it new in San Francisco. His parents kept it for him until we we were in a position to keep it. His dad hired professional piano movers to get it from Madison, WI to Maine. My daughter has no idea how lucky she was to grow up playing it! She’s studying jazz piano in college now, as an extracurricular activity. 
If you like the piano enough to want to keep it, get a professional mover, you won’t be sorry. If the piano is not particularly expensive or of sentimental value, I would recommend selling it where you are (sounds like the OP may be able to sell it to the home buyer, which is a win-win) and buying something there. It isn’t like moving a car, when you move a piano the movement itself, the vibration when it is driven down the road, changes in temperature and humidity, can all effect it, and if you move it yourself the likelyhood of issues will be higher than with a pro doing it (assuming they have experience with pianos, not just a mover:).