Verizon’s rebate offers are strange. I have a family plan with 6 phones and it was an older plan, not unlimited. We had 40 GB/month for data, so it was essentially unlimited. On that plan, the trade-in value for the S8+ was a bit over $100. I switched the plan over to unlimited, knocked about $40 off the monthly bill, and qualified for the $500 trade-in.
I just pulled the trigger on a Note 20 Ultra 512 GB today. I usually keep the previous phone as a backup, but Verizon offered a $500 trade-in for my Galaxy S8+. Of course, they didn’t have any of the 512’s in stock, so I have a couple of days to get all the images/videos off the old S8+ before switching over.