There are services where you can drop off eligible items, and they will research them, photograph them, post them to eBay, and ship them. This wouldn't handle the temporary-storage model, but they do handle everything related to selling.

They are nice in that you can just drop stuff off, never see it again, and sometimes get a check in th email. But the downside is that after fees and percentages, you see about 50-60% of what the item sells for. So it's good for boxes of old stuff that have some value, but that you know you'll never break down and sell individually.