Can you trade in a 4s for a 5?

So when I got my iPhone 4s last year when it came out I was told that when the 5 was released at a apple retailer I would be able to almost trade in my new iPhone for credit that would help pay towards the iPhone 5 so it would be you know somewhere around $300 or something. I don't have a update so this is my only choice and I plan on getting an iPhone 5. Can anyone tell me how excatly it works, or if that's even the case?

If you are under a contract, you either have to pay FULL price for the replacement iPhone 5, or you need to pay an early termination fee on your current phone and get the new one… Either way, its likely going to be around $600

Sell it on ebay.

No.
as soon at the iphone 5 was announced, the 4s value dropped to $250.
so a use 4s will be $150