The down payment is for any option higher than 32gb with the plus models. I'm not sure if you maybe got a 16gb last year or the non-plus model, but you should have paid down payment if you got anything higher. I remember last year paying $100 for the 64gb plus model. Or what buckeye said, you might have paid a higher lease monthly. It does end up coming to about the same price.
Thanks, I did do the 128 last time and I traded in a phone for lower payments, I may not be recalling paying a down payment and maybe i did, it's almost 5am here.