$120 a year and it's a needless cost for anyone trying to get into gamedev. The pay-when-you-make-it approach of UE4 and Unity is much easier to stomach when you're new.
True. But the answer to
If you're a developer, is it still worth paying for a game engine?
Is equally simple.
If it benefit you more / give better results / save time which out-weights the price then sure it is.