ffs...
the next deals aren't "expensive" (nor are the comparable VZW, Sprint, etc stuff)
You are paying full price on the phone either way, whether you buy the phone off contract either from apple or through one of the installment programs, or buy it at "upgrade pricing" with a contract.
my bill with AT&T under contract for 5 lines was around $300. My bill for 5 lines under Mobile Share Value (no contract, no subsidies) is under $200. I am literally saving over $600 per year off of my bill... Now assume I upgrade all 5 lines over 2 years..
$300 x 36 = $10,800
5 x $0 (free phone worth $450) = $0
Total = $10,800
$190 x 36 = $6840
5 x $450 (free tier phone) = 2250
Total = $9.090
Now let's take the top end iPhone 6 Plus
$300 x 36 = $10,800
5 x $499 = $2,495
Total = $13,295
$190 x 36 = $6840
5 x $949 = $4,745
Total = $11,585
And that's if you upgrade within every two years. If there are phones that go without upgrading in two years (a mom's phone, kid's phone, etc) you save even more.