There's nothing wrong on having that self reward and you do really that deserve it, specially if you have been long time saving up and sustaining all of those tough situations then buying up something for that hard work then its not really that bad at all. Just make it sure is that you wont really be that spending a huge amount or partition of your money. If its really that a huge amount that you do currently have then taking up some slice then its just really that fine but if its opposite then that should be a no go. You would be able to think about that there's so much important thing that you do need to prioritize on.
Investing while considering on buying an iPhone then its a no brainer on what are the things that you would really be needing up to prioritize. So it will really be that up to you on which one you would be choosing.
If you do want to save it for later then you can do but if you cant be able to wait then it will really be that up to you which one you would choose. You can see be able to make up some comparison in between decisions then you can make out point on which one is better.
People would prefer to live a horrible life that has absolutely no taste for 30 years, just so they can grow up and be fine when they are older. They are not even realizing what they are trading, because they are losing 30 of their greatest years, and instead they are being cheap and having no fun so that they can be wealthy.
This isn't about an iPhone by the way, if you do not want to get one, then don't, it is not really a big deal, I don't have one because I never felt the need to spend that much on some phone, why would I, but that doesn't mean I invested every dime I make neither, I had a good life. Sure I am not rich thanks to that, but I had a good life with my loved ones and I am happy with that in most cases.