My understanding is that Optical SFP/SFP+ transceivers have a finite lifetime and it's in years, not 10's of years. This would seem to mean that buying used and "refurbished" transceivers on eBay isn't all that prudent. Sellers seem to be pretty generous with their meanings of new and "New (Other)" too leaving you unsure if they're really new and unused so is it best to steer clear of eBay for optical transceivers?