Sorry to hear about the loss of your friend

I would first try and discern the family's wishes and provide them reasonable expectations. If they are really planning on "just donating to good will" that seems to indicate minimal attachment or desire for financial return. Would they be happy to just see these go "to a good home?" If that is true, that gives you quite a bit more leeway in how to go about this. Might allow for donating locally or here on "pay it forward" or Selling at lower/reasonable prices for quicker sales. Whether it is just "finding a good home" or finding a buyer, as others posted above there is a trade-off with the time it takes to make that happen and how well it gets done. What is the time frame? Do you have a place for them if they need to move?

You could always throw some pics up in the Appraisals thread and get folks here to help gauge value/desireability

best of luck