If you never use your iPad and you already have an iPhone, then why keep it in the first place? I'm sure you can sell it and use the money for something else. Otherwise, if you see that the S3 might be useful somehow even though you already have a phone, then make sure it's in a good condition and go for it. As for me, since you asked if I would do the deal, not really; I'd either keep the iPad 3 and find a use for it or just sell it and use the money for something useful.
Deal is done. Got the Galaxy S3 and love it. I was in a car accident recently and it looks as if I'm going to get a substantial pay out. So if I feel the need for the newest iPad when that surfaces Ill get one. And my mother always taught me. If you have nothing useful to say then don't say anything at all.
I think some people don't get the concept of used. When you receive a case that is all scuffed up. Had glass in it from where some kid dropped his phone in it and it smashed a glass panel and the case no longer being waterproof. You no longer get full retail price for it. Just saying.