Buying Pieces of Sets to Sell at a Profit
"Why do you have five copies of this book?" a relative asked me the other day. I had to smile. On that shelf, I keep multiple copies of the individual books within a six-part set which sells very well. (Truly, I haven't paid enough attention to completing the sets, which is why those five same books were still there).
When I get all six copies in a set, I list the set on eBay or Amazon, and sell it at a profit.
This is something you can do, too, when you are buying inventory online (if you are not already doing it). What you want to do is look for items (they don't have to be books, though that is a lot of what I sell) that can be put into a set, and are reasonably or under-priced. You can even use the BAM Seeker tool to do this!
One example of this is the Harry Potter book series. You can find examples of sets for sale that have all of the books in the series, or just several of the books in the series. You also don't have to look just online for this inventory...you can find things like nice, hardcover first American editions of these books at yard and estate sales...just make sure they're priced low enough (like $1 or maybe $2) so that when you put them all together as a set, they will make you a decent profit that is worth your time.
What's an example of this? Well, an extreme example would be a listing that's up now on eBay of every book in the Harry Potter series, all first American editions, for $2495. (These are not even the British editions, mind you).
In terms of books, you can look for paperback books to put into sets, too. Right now there is a paperback 1st American edition of Harry Potter and the Sorcerer's Stone for $3.94 on eBay. There is also one at a much lower price but at auction.
This doesn't mean you can make this kind of money on Harry Potter sets or other sets, but I have found that the popular set of things (be it books, charm bracelets, dishes, or what have you) will sell and re-sell, if you can identify what they are.
Happy hunting!