I remember the last time had a piano to get rid of. Darn near had to pay to get rid of it. Must have contacted a dozen places to donate: No, thanks we don't need no more stinkin' piano donations!! Finally found a guy with kids wanting to learn to play with several strong friends, piano jacks, and a truck. (I have gotten rid of two pianos in my life, neither was all that pleasant an experience.)
That said, I am in the process of downsizing as well. Some stuff will sell, some will be donated, other stuff will be put on the curb and listed as a come an get it on the neighborhood boards. More will relegated to the landfill. Moving and storage costs can be reduced if you plan ahead. I know people who shipped a rock collection (not precious stones, just rocks they fancied) and another who shipped an enormous collection of National Geographic. But to each his own I guess.
BTW:
Anyone interested in a slant six 1968 Barracuda fastback, speak now or forever hold your peace, it has to go too.