Experience signature?

So I’ve been with TMOBILE since they took over sprint. They made me go to experience signature. But now I’m trying to upgrade my phone. I was talking to a representative and she said for me to save with 2 phones I should switched to experience beyond? But I think I’ll be paying more. I am trading in my iPhone 17pro max in and the credit they give was $470. But it’s one time credit which I don’t get? Would it lower how much I’ll pay a month for leasing the phone. I don’t have to pay a Down payment.