I could never get rid of the "spare" stuff. Every now an then I may sell a little. A friend of ours had his boat cleaned out at his house of all places. They took everything from electronics to all tackle. I helped him out with 8 or so rod combos and couple tackle boxes of lures. But that was the most I have ever parted with.
My grandfather left me a storage building of tackle when he passed from our days on the water. Some days its a bad thing being hard to justify buying anything new but others I see it as he took care of me long term.
That was part of the appeal of flyfishing...we didn't do that.
Actually got to buy stuff.