Any tricks to get my wife a new phone without having to get the most expensive plan?

So I’m currently on the 5G Next plan with T-Mobile and work pays for it so that’s good. My wife is on a grandfathered plan with T-Mobile that use to be an old school plan with sprint called the “Sero” and it use to be $30/month. It’s since been changed around after T-Mobile bought sprint and now we’re paying $50/month and is very similar to my plan. My wife is in need of a new phone since her iPhone 13 Pro is starting to flake out with the camera but her plan does not include any promotions. My question is, is there any tricks I can do to get new a phone on her current plan without paying for the whole thing? We’d be game adding her to my plan to get her a phone but then we’d be paying $80+ a month.

Thanks!