As stated in the title, this may be YMMV but wanted to share. Here are the steps I took to get Verizon online customer support to offer $1000 trade-in over 36mo via email (screenshot below) as well as waiving the $35/line upgrade fee for 4 phones/lines. This is enough to get the equivalent of New Customer pricing as an existing customer. My trade in phones are iPhone 11 Pros, FWIW.
1 - After the new iPhones launched, I chatted with Verizon online chat asking if they could match the new customer pricing deal for existing customers otherwise I would just switch to get $1000 trade-in and free activation from another carrier. They declined.
2 - Approx 1 week later, I received a "just for you" offer via email. Screenshots attached. I chatted with Verizon online chat again, this time with my cart loaded with the 4 phones I would purchase and asked if they would waive the upgrade fee. They declined. I again said other carriers would waive that fee ($140 for 4 phones) but they said the fee was accounted for in their new trade-in offer of $1000. I said ok and emptied my cart.
3 - 5 days later, Verizon sent a follow-up "your offer will expire in 2 days" email. I again loaded my cart with the 4 iPhone 14 Pros I would purchase and used chat to ask if they would waive the upgrade fee. This time they did. The customer service rep added all of the phones and upgrades on his end and pushed the final order through. Screenshot of one of the phones on the final order attached.
Just asking for what I wanted netted an additional savings of $235 per phone or $940 in my case.