Google created AMP as a ligtning fast mobile first framework for building websites. It's especially good for business websites, since mobile speed and functionality is increasingly becoming a ranking factor. The faster your website loads on mobile the less advertisements will cost you, not only in Google ads but Facebook too. The idea is that they want a fast, seamless experience for their users.
An AMP website wont necesarily cost you more, in fact ongoing costs like hosting will be much less. AMP websites are known to pay for themselves in improved performance. However only professional developers can build AMP websites because AMP doesn't have a content management system like wordpress. You just have to pay for the time it takes to build your website.
Here's a more technical explanation of how AMP websites work.
Get in touch and find out if the AMP framework could benefit your business.