I just ordered some LED light bulbs for the house recently. I couldn't remember which ones I wanted to get (I knew they were Phillips, but nothing more), so I did a search on 'led light bulb' and clicked until I saw a page that said that I had ordered them before.
Unfortunately, the ones I really wanted were the L-Prize ones (which I'd also ordered before), which are a bit brighter and use even less electricity.
I figured I'd just return the ones I'd bought, and get the right ones.
Then I saw how much it was going to take to ship them back (about $8 for five of them), and had to think a bit more. I worked it out, and the two lights use little enough electricity that the return price, combined with the difference in purchase price, was about the same electricity (would have been a bit of an edge in favor of return, if I was in California, I think). So I guess I'll just keep 'em and get the right ones next time.
And I think I'll put a note in an amazon review, to keep anyone else from making the same mistake.