Counting Eink only.
I had 3 and I sold one. I didn't want to sell it, but was to a good friend who was having trouble getting one.
I bought 2 more and I gave one away. I was not using it so was happy to give it away.
No doubt I will keep on this way.
I have 3 now and do use them all, although one less than the others.
If you use them all, you should be allowed to keep them all
. If you have to talk yourself into using one or more, than maybe dispose of those while you can still get a return on them.
Helen