I just give to the local co-op. It can be written off as a donation since it is a registered non-profit.
Note this is for smaller things. All the bigger things I just sell locally, but I have used eBay for non-bike stuff with success. I got a 1099, but it was below cost sales so it is a non-issue. The main problem I have had is selling really common things like iPads etc. Lots of scummy buyers trying to scam out there. The more obscure the item is the less you have to worry about scum buyers.