hmm, I would say you just bought a $11 letter opener and I wouldn't advice to resell it - you're just perpetuating a useless piece of steel. May be the scales could be reused...

You didn't read the stickies in this section did you? Don't worry, you're not the first one to make the mistake and won't be the last, but don't hesitate to ask for advice - people here have a lot of experience and are more than willing to help.