Great point. Also, on AWS if you use Amazon Linux you are even more 'locked-in'. Maybe that's the reason many hosting companies give you discounts at the beginning.
One question. If real hardware was always 50% cheaper then AWS wouldn't have been such a success. Can you please explain in which scenarios it makes economical sense to use AWS compared to real hardware?
In this life very few things are black and white. Getting a gold badge in Python is not as great as starting the next Facebook but it's definitely a clear sign that you know your stuff.
I think your badge is worth much more than $3, but it's very hard to value how much money it's worth. Think about it: how much money is worth getting a GPA 3.7 vs 3.3? How much money is worth meeting Zuckerberg and talking with him for 30 minutes?
Getting a gold badge in Python will not result in a rise on your salary alone. On the other hand having this badge proves that you know your stuff. It's clear how competitive StackOverflow is. If you ever decide to move to another company it will definitely be seen as a positive sign when they look at your CV. You may get an interview thanks to the badge.
So, to sum up, with this badge and some luck, you can work at a better company (and this means higher salary). On the other hand, don't expected a rise from your boss.
It's really sad to see a company end up like that... In the end, you should only risk what you are prepared to lose. Those guys maybe risked a bit more than that.
I think you should not worry about your age, after all there is nothing you can do to end up younger. You should have confidence; you are much more experienced than the average 25 year old developer out there.
On the other hand, as others have stated, you better avoid making your age obvious.
In the end, you know what? In this life your time is limited and I think it's wise to avoid worrying about things you can't control. Don't make your age obvious but have confidence in your skills and experience!
Facebook and Google use Machine learning algorithms to increase Ad revenue and serve more relevant information to the user.
Machine learning is also used in health care to predict Emergency Room wait times for example.
Many banks and big online retailers use Machine learning for fraud detection.
And of course Machine Learning is used in the stock market.