Which, as people here mentioned, shouldn't really be your main consideration. If you wanna keep programming in PHP that's perfectly fine, but all in all the minor price difference between stack hosting prices is a poor excuse to justify it.
This is the specific type of situation that PHP is almost ideal for because it scales down better than most other languages since everything is loaded and processed on-request instead of booting up to preload. You can host 1,000 PHP sites on a single small server as long as the concurrent traffic doesn't outstrip the specs. With most other languages that have to boot and preload, you're restricted before traffic becomes a consideration.
PHP's not the right choice for every situation but for his use case it's pretty solid.
Yes of course, I agree that it shouldn't be my main consideration. I will think about it, since I really want to switch programming language.