Using PHP just because it's easy install isn't like buying a cheap car because it's cheap, it's like buying a cheap car because it's just a little bit closer to walk to than another cheap car.
To the extent that learning languages takes time (it does) and to the extent that setting up an environment takes times (it does) and to the extent that time is money (it is), I'd say using PHP in lieu of a premium language is exactly like saving money on a car when you don't have a lot of [time/money].
But in the end, what's most important is that the car/language gets you from Point A to Point B.
It's only saving money when you don't count the ongoing opportunity cost of using inferior tools and technologies, but that's a false economy. It's a short-term savings in exchange for lots and lots of serious pain going forward.