TL;DR:These comprehensive online courses can teach you what you need to know about a variety of subjects, and you can score any one of them for $15 and under in the Mashable Shop. 

Gone are the days when scholarships, prior degrees, a trust fund, or even a physical classroom environment were needed to further your education. Today, all you need is a computer, an internet connection, and a pizza. Especially the pizza.

Anything you’ve been dying to learn? There’s a course for that. No, seriously. There are online courses in just about every topic you could possibly imagine — and they’re all at your fingertips. 

Right now, these 10 e-learning courses are on sale for under $20 each. So if you’re hungry for knowledge, pick a class and feed your brain this month. Netflix can wait.

1. The Complete Blockchain Professional Course

If you’ve always wondered how the heck Bitcoin works, this course is the perfect opportunity. This beginner-friendly six-hour course teaches you the ins and outs of blockchain — the technology that fuels Bitcoin and other cryptocurrencies. You’ll learn how a blockchain transaction works, key concepts, and all that this technology is capable of.

The Complete Blockchain Professional Course is just $9.99 on sale — down 95% from its usual price.

The Complete Blockchain Professional Course — $9.99
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2. The Complete YouTube Master Class

It’s no secret that you can make a ton of money creating videos on YouTube. But how to go from YouTube viewer to YouTube creator is a different story. This Complete YouTube Master Class shows you all the steps it takes to build, maintain, and grow a budding YouTube empire — from starting a channel to getting subscribers.

This training is on sale for just $11 — 77% off the regular price.

The Complete YouTube Master Class — $11
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3. The Content Marketing Master Class

In the internet age, customers can easily tell who puts time and effort into their content marketing and who does the bare minimum. A strong web presence consists of a variety of content — from graphics to blog posts to videos. It’s no easy feat, but this Complete Content Marketing Master Class will give you the tools to create content that converts. In just five hours, you’ll be one step closer to reaching your business goals.

This course will cost you just $11 here — 77% off the original price.

The Content Marketing Master Class — $11
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4. The Communication Skills Master Class

The ability to communicate effectively is essential in basically every industry — whether you’re an artist, a data scientist, or a lawyer. And taking the time to develop your communication skills can help you get better jobs, land promotions, improve your relationships, and just help you be more successful overall. This 29-hour course will help you hone these skills and become a master of persuasion, assertiveness, and more.

Enroll in the Communication Skills Master Class for just $14.99 — 92% off retail value.

The Communication Skills Master Class — $14.99
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5. An Entire MBA in 1 Course

If time and money are standing in the way of you going to business school, try out this: An Entire MBA in 1 Course. Led by award-winning business school professor Chris Haroun, this course teaches you many of the basic skills and concepts you’d learn in an MBA program in just seven hours. You’ll discover how to launch a company from scratch, how to create financial models, and even learn how to get investors.

Better yet, it’ll only cost you $10.99 – 94% off retail value.

An Entire MBA in 1 Course — $10.99
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6. The ‘Become a Wedding Planner’ Course

Aside from getting to share in the j