Ridiculous Down Payment

You make a fair point. Part of what I'm trying to convey, though, is that a $35k item is something that requires more investigation and consideration on the part of the financing bank, than is an $800 item. I think we can agree on that.

The credit check done by T-Mobile, or Verizon for that matter, can't have too much thought placed into it, based on the literally instant decision. I would assume there's some sort of algorithm used by a computer to offer these instant results.

I could afford to pay the $700, but at that point why bother? As I said in my OP, if I'm going to pay that much, I might as well just part with the remaining $150 and buy it outright. Which, again, I could, but have no desire to and no need to. I want to switch to T-Mobile, and I assume that T-Mobile would prefer to have me as a customer as well. It's just that I could pay $0 if I stay with ATT or even switch to Verizon. That makes it a lot harder for me to justify leaving. Surely you can see where I'm coming from on this?