It's funny. I'm in the EXACT same situation. I have a Galaxy Tab 2 and an iPad Retina but I need something for the gym. I have a smart phone so I felt like I don't need the screen of a Nano or full iOS of a Touch. But if I buy a Nano and a set of earphones, it'll be over $100 anyway. And with the $229 Touch, that becomes close to reach anyway.
I have a $25 off $100 coupon for my bookstore. I was thinking of getting a Shuffle with a set of SOL Republics or maybe some Sennheisers. The thing is, the Earpods with the Nano would defeat the purpose. However, we're still talking about a $100 difference.
This is such a hard decision to make.