Check my math
I am currently a google Fi customer with 3 lines. I have a Pixel 8 pro and I'd like to upgrade to the 11 Pro 512. If I do a straight upgrade it's $550 off the phone and works out to $27.88/m for 24 months. The other offer is add another line which gives only $300 off the phone but $799 back over 24 months on the plan. It looks cheaper to just go to 4 lines even though I don't really need it. Am I missing some catch?