Refurbished items are a great way to get a discount on something that will look and work like brand new. It makes a lot of sense for gear I buy that will be used overseas. A longer warranty doesn't make sense if there's not a convenient way to get the item back to the US for repairs. And we nearly always unbox items for travel to save on space, so the packaging is irrelevant.
I do a lot of shopping on eBay, if only to get an idea of the market. eBay’s size and low overheads for sellers make it a great resource for finding out how much things are really worth (at least for things with reasonable liquidity). Check a Flip (which uses eBay current and historical prices) is a fantastic resource for getting a rough average of a particular item. Be sure to weed out broken items sold for parts, or actual replacement parts for an item!
On eBay there used to be just 3 options for condition: new, refurbished, or used. But savvy sellers started listing used items as “refurbished” to command a higher sale price. And sure, some sellers do go the extra mile to clean up a used item. But unless you are truly restoring it to "like new" condition (for example replacing the battery in a laptop so it has no power cycles), then it's not really refurbished, it’s just used.
eBay now has values for “Seller Refurbished” and “Manufacturer Refurbished” to distinguish these two cases. I always filter out the Seller Refurbished items, unless I am looking for something used (and even then I often do because I think anyone who uses “Seller Refurbished” is arrogantly trying to get more money than something is really worth). I recommend you do as well.