I also prefer to up front whenever possible and never had a phone paid by contract. I buy an iPhone preferably used and use it until major OS updates are no longer available. I currently use an iPhone XR from 2018. I think that long term with iPhone it’s cheaper than doing the same with Android unless you go with really budget ones like 150 €, but that’s to bad of an experience for me. What I also really like with iPhone is that you can get really cheap displays and batteries which is not the case for Android phones in my experience.