By the time I hit the 'order' button, either for a pre-order, or an in stock item, I already know beyond a shadow of a doubt that I want the item. There's no second guessing, or buyer's remorse, guilt, or whatever. I don't jump at flavors-of-the-month, or buy something just because I need to buy something. I'm very thoughtful about what I buy.
So when it arrives, I pop it out of the box, set it up on the shelf, put the accessories in one of the storage bins, and toss the packaging like the trash that it is.
I don't buy stuff with the idea of selling it later. Why would I? It's a hobby, not a business, and I only buy what I really want.
IF I ever do decide to get rid of something and I loose a few dollars because it doesn't have the box, well, so what? I got my money's worth already. I didn't buy it to make a profit. Hopefully the next person will like the break he got on the price and enjoy the item as much as I did.