Can I trade my iPhone 5S in for an iPhone 6?

I know the iPhone 6 isn't out yet, but when it comes out, do you think I'll be able to trade in my iPhone 5S for the iPhone 6?
(I have a two year contract if that means anything.)

Depends pn where you are in your contract and which carrier you have. Some allow for early upgrades.

Certainly you can! It will only cost you a couple of hundred bucks and a new contract.

No Understand that when you purchased the iPhone 5s they allowed to buy it for less that full retail because you in turn "promise" to be that cell carriers customer for 2 years. Now if you purchased an iPhone 6 you would have to purchase for full retail price Now if you sold your iPhone 5s On eBay then use the proceeds toward an Apple iPhone 6

Depends on the carrier & if they would give you the option. Usually if that is the case it would depend on when did.

No just sell your old one

Trade in? It all depends upon what you mean by "trade in". They will be happy to sell you whatever you can pay for.

IPhone 6 has not been released yet and no information has been given whether Apple will allow you to resell your old iPhone for an iPhone 6. Since some apple stores have done it it could be possible for them to do so when it is released.