I don’t like spending money on boxes and packing material. And like many other small eBay merchants, I’m guessing, I save the boxes and packing material from shipments to me for re-use. Well, only sometimes. Unusually sized or shaped boxes I see infrequently, for example, that I think I may have some use for later on. But the commonly seen stuff? Out they normally go with the rest of the trash, unless I can turn them around incoming to outgoing quickly.
There’s the storage issue, of course. But even more important, there’s the time thing, which frankly is probably the small business person’s single biggest profit and opportunity killer. In my experience, prepping old shipping material (such as peeling or scraping off revealing labels from boxes) actually triples or even quadruples the time it takes to package and ship an item.
Got better things to do with my time.
Sure, if you’ve got more time than cash, go ahead — save, store, prep and scrape away. But I’m telling you, when your operation’s solid and steady enough, look into getting the shipping supplies you need fresh and spend whatever time that actually frees up on more productive (profitable!) activities.
Having said that, there is something I use regularly in my packages that I never purchase: filler. Besides the fact that I don’t often deal in breakables that require special filler packing, I’ve literally got an endless supply of professional (unlike some of the really weird packing material some folks have used), flexible, usually sufficiently shock absorbing, and easily disposable (even biodegradable!) filler material… and chances are so do you: the shredded paper from my paper shredder.
Thanks to identity theft, paper shredders are now de rigueur machines for the home. And I know I’ll never run out of free paper to shred; it’s called junk mail. I can’t remember a single day when I didn’t have a small stack of it to feed through the old workhorse shredder. In fact, there’s so much of it, I always have more shredded filler than I need. Finally, something good and useful from junk mail. 
Besides the usually small shredder waste receptacle, I’ve found it sufficient to keep an extra medium-sized box of shreds handy. Anything more than that gets trashed.
Get the best paper shredder you can get… unless you like handing over easy-to-piece together paper strips of your financials and other private information to your customers.
