Hi so i actually work for Verizon so let me help!
I can't speak to what apple is doing through their website but if you buy it through Verizon:
If you're on the following unlimited plans:
Play More, Do More, Get More, Above and Beyond:
Then your iPhone X is worth $1,000 off the iPhone 13 Pro and Pro Max. Or $800 off iPhone 13. In other words, you're not gonna get MORE than what the phone is worth.
SO the 13 Pro 256 you want for $1099 will be only $99 or $4.16/month for 24 months. Technically you're not supposed to know about the $1,000 promotion so i'd suggest doing it though Verizonwireless.com