If you can't upgrade a line, or if you can't afford to do it and still have savings (seriously, the threads about buying a phone on credit are hilariously sad), fine, but the 5S is WELL worth being paid to upgrade.
I have 5 family lines. All mine (2 are kids, 1 mother in law, 1 wife that doesn't care about the latest and greatest). 3 are 9.99 lines with data blocks that run me 120 bucks a year each. The other two are more of course, but we USE the crap out of them
Every year I profit from upgrading. It's gotten less and less now that Apple has globalized the phone, but my 5 still sold for more than I paid (subsidized yes) for my 5S.
Next year the 5S will likely fetch 4-500 again. Upgrade lines 3-4, make $50 or so bucks (even after the fees) rinse, and enjoy the 6.
Now before some smartass jumps in and tells me about service costs and whatnot, it's not money I'm just throwing away: I gladly pay for the fastest (unlimited too) LTE, unlimited messaging, and minutes. I don't consider a contract any sort of penalty when it's something I want.
Soon I'll probably only break even, maybe even lose a bit, but it'll STILL be worth it, because I'll always have the latest and greatest, and won't have to decide if it's worth it (and so far it ALWAYS has been, even without the profit).
So ya. Yawn. It's an awesome phone, better than the 5 (faster, better camera, better battery life, touchID, better color combo, better resale, dual flash...), and I'll still get the 6 in a year and get paid again for the privilege. Yippie!