Keep them, small box will act as storage. As said if you sell a scope or whatever then you have an eyepiece or two to go with it. All my astro bits get wrapped and stored in a plastic storage box. Easy to find and easy to drop bits into.
I tend to help at outreach and have set up a few scopes for kids and I have just given them one that works better then the things they received with the scope. It is amazing how much better a plossl is over the lowest cost items that come with the scopes.
Equally if they weren't lowest cost half the kids wouldn't have ever got a scope. Last astro show I was at I picked up 3 plossls at £5 each, ideal to say try that, then tell them to keep it if it gets the results.