Dear Lynne,
thank you for posting the information about the A3000, A500 & all the hardware and software.
I can see your father was a dedicated enthusiastic Amiga user and follower of the Amiga community (look at the software & hardware).
I bet there are lots of files pictures & information stored on the floppy disks and hard drive, from years gone by, & may help remind your father of time spent with his Amiga.
Yes the A3000 Tower is worth a number of $$$ and is a legendary & special computer desired by most of the Amiga community.
I have tears in my eyes reading your story, but hope that maybe some of the information retrieved and the items sold will bring a little help and a feint spark of treasured memories.