This is what I've been wanting to do, but I've found the used iPhone prices to be frustratingly high.
Maybe I've been looking in the wrong places, but I can't even find a base iPhone 13 for less than ~$550. Does it really make sense to buy a 2 year old model for 30% less than the brand new version? Sure, there haven't been many meaningful improvements in the past two years, but its still two fewer years of software support.