If you are riding your bike without pain and no discomfort from my point of view save your money. I have been doing bike fit assessments for years. Sure I could find something to tweak... but why? Ride your bike, have fun, be pain free. Some day you can come see me or another fit specialist... when you want to address pain if it ever occurs), be more efficient (when you really care), etc. Until then just ride your bike.
It would be if I knew they would do a better job than what I can do myself. The trouble is finding experienced fitters who really know what they are doing. I wound up eliminating about 90% of my knee pain by using an iPad app called "coach my video". I filmed myself on a trainer and measured various angles and found that my seat was a bit low and too far forward. Tweaking it up 1/4 inch and back made all the difference. Also, doing kettlebell swings and snatches really helped with avoiding Tband issues that contributed to the pain. Oh, I also put in arch supports too.
If you are serious for cycling, it is worth. However, it is not necessary though because you can browse a lot of Youtube videos that can show you some basic to professional suggestions. You may save some money for purchasing cool and awesome cycling clothing !