Read what you said in bold. Just because YOU do not see the need for a new phone, and would rather spend it on photography, does not mean he feels the same way.
For you, a phone may just be a simple tool, but for many of us, myself included, phones are a hobby. I get new phones every year, sometimes more often, not because it does things differently per say, but just because I love technology and love smartphones. You may be happy using a $150 Moto G, but I know I sure as hell would not be.
He has $300 to spend. Why do you care if he spends it on a phone, or spends it on a cheap laptop or camera? If he really likes phones and what they offer, more power to him.