https://forums.macrumors.com/threads/how-long-do-you-plan-on-keeping-your-x.2081595/liked-posts
^ The reply from Spink10 was the only answer I liked. Wisdom.
Think ahead and be aware of your finances. Don't be prisoners of the moment. Those bills after awhile will start to pile up.
What is sad is a better one will come along and be cheaper. I get it that it's a special 10th anniversary iPhone. Alot of us just refer to it as The X. Sounds cooler to say. Doesn't mean that every anniversary iPhone will be amazing. It's like sports. We don't know if the next game we will watch will be the best ever.
The iPhone in 2018-2020 could all be amazing and surprise us with even more features. I realized picking between tick or tock models is a waste of time. They all improve every year. Since when has it gone backwards? What matters is if those improvements are worth it. To some, not really.
We don't know the future. The iPhone in 2019 could be downright amazing too and with features that might unexpectedly surprise us. The next iPhone doesn't have to be an anniversary model to be the greatest...
Depends on your situation.