Meaning, as a baseline, if I pay for a training I'm going to get more out of it because I'm psychologically motivated to do so because of the financial investment.
There are other ways to make someone "feel like they have skin in the game" but a price tag works.
The most recent online training I purchased was Brennan Dunn's "Double Your Freelancing Rate" course and it was definitely a good investment for me. It's easier to justify a course like this because it more of sales / marketing training and can quickly pay for itself in new business it helps you generate.
I used to subscribe to Avdi Grimm's Ruby Tapas which was another great investment at the time. I haven't purchased any of his courses, but Wes Bos looks to produce good premium content.
Before I subscribed to Safari, I subscribed to Packt Publishing's similar service ($100/yr) at the time. They also have video courses, but mostly books. All of their books are on Safari too. I found this so useful that I "upgraded" to Safari after the first year.
Outside of programming, in the days before MOOCs were popular, I had purchased a lot of The Great Courses classes. They are top notch, and live up to their name. Most of the ones I bought were on art history, general science/astronomy, and history. They are very in depth, usually anywhere from 30-60 hours of lectures, plus reading materials. I know they have a subscription service now, but last I checked the courses that would interest me most were available as part of that. They did (maybe still do) play games with their prices, having them cost $300-$400 regularly, then going on sale for $100 or so every year. You might also look for used copies on Ebay.
So I'd say it was worth the ~400 bucks.
Of course you get out of it what you put into and paying money to learn seems to be a good motivator to learn etc.
In my experience the courses are fairly comprehensive, and the quality of the videos is high.
Pluralsight started out fairly Microsoft-heavy, but their course catalog is expanding all the time into different platforms and technologies.
For what you get I think the price is reasonable.
Anecdotal: I tried learning angular2/TS through egghead but found I wasn't grasping simple fundamental concepts though the videos were quality. Tried pluralsight and they start from a point that gradually built my confidence in my knowledge. Been doing more and more courses on there pretty decently.
I will continue to checkout egghead first and pluralsight second if I'm not grokking it.
Disclaimer: Prior company provided egghead license, current company has a pluralsight employee license.
I wouldn't pay for online course to learn technology or language that contains piles of long videos.
However succinct, compressed course that explains everything in a couple - to - few hours - would be a good candidate.
Having someone experienced explain not only what to do but what _not_ to do is extremely valuable.
Highly recommend it if you can devote a chunk of time to complete each course in one or two sessions.
The momentum in each lesson plan is significant and easily lost with a break in learning.
I've only done it twice. Back in 2008 I was trying to transistion from a C/C++ developer/bit twiddler to an "enterprise developer" using C#. I did the 6 test track and knew enough to have a broad overview and was a much better interviewee. I never put the certification on my resume.
Currently, I'm working on an AWS Certified Solution Architect Associate cert as a software architect, I need to know what is out there and it's forcing me to learn. I'm watching PluralSight videos, reading the books and watching YouTube videos.
Also of note in the React Universe is Cory House. His teaching style is good, but he cracks too many bad jokes for my taste.
I'm a real person who benefitted from these courses. Not everything on the internet is a shill or a scam
However, are you the kind of person who can power through a course? Do you need a project to work on? Do you need peers and a live tutor?
First, know thyself.
If you are willing to put in the hours, then the actual cost of the course is miniscule by comparison. Udacity and Coursera (and EDX) let you audit the courses for free anyway.
Although if you're already in tech, it probably would be less than productive.