The ADA itself holds different organizations to more/less stringent standards based on a host of factors, government funding being a major one. Government agencies themselves are usually held to the most severe standards. That said, while ADA has adopted WCAG as the defacto standard, from what I’ve seen it appears they’re going with AA compliance as the most reliable one. That said, we’ve done work with some organizations who’ve chosen to comply with AAA in an effort to be as buttoned up as possible from an accessibility and experiential perspective. We’ve also worked with some who have tighter budgers and aim for level A compliance and have a more “react and repair” mindset when they discover anything in their site that is giving someone hardship from an accessibilirt standpoint.
I am struggling with this right now. Alt text, captions, audio (read to me) options are good. I work with an accounting software app that redesigned its palette to red, black, and gray. No green to signify income. Made no sense to me and their gray text (also very skinny sans serif) made reading many nav bars difficult. Some URLs are accessible from the build-out, but the DIY sites often don't have the same capacity. As with secure sites, I think google will be downgrading those sites with little or no compliance or accessibility add-ons.

The gray area is a matter of scale and purpose. If you have a small business which serves as specific market it's a good idea to make the site as user and disability friendly as possible. If, however, your market serves segments with a likeliness to have various handicaps or disabilities you should address that with an ADA Compliance review of the site. Also consider the scale and purpose of an organization. Publicly traded large businesses need to concern themselves more than a single location family owned retailer and if someone sues your flower shop because the text was too small or didn't have "image alt tags" causing them distress... That's pretty frivolous and would likely not stand.
The average cost for hiring a web designer varies greatly depending on the scope of the work, which may range from building a site from scratch to rebranding an existing one, as well as the amount of content and graphics the designer will create. In general, the more complex the project, the more time the design agency will have to spend. Because web designers often work on an hourly basis, the longer the project, the higher the costs; you can count on the web designer spending at minimum 10 hours to create a very basic website with just a handful of pages with few elements. Prices also depend on the designer’s skill set, the process, and the company’s rates. In general, the national average cost for a basic website package starts at $500, but a customized website can cost as much as $2,000 or more. Here are typical average hourly rates, broken out by the complexity of the work:
Title III of the Americans with Disabilities Act (ADA) prohibits discrimination on the basis of disability in places of public accommodation, including restaurants, movie theaters, schools, day care and recreational facilities, and doctors’ offices. All public places, as well as privately owned commercial facilities, are required to comply with ADA standards.
The Americans with Disabilities Act (ADA) was first passed in 1990. Twenty years later, the US Department of Justice released an update called the 2010 ADA Standards for Accessible Design. These standards cover the design of physical spaces and have been interpreted to include web locations as well, so it can be difficult for the would-be accessible website designer to use them.
I have previous experience with a company that sold a platform to help alleviate ADA compliance issues on websites. From my understanding litigation is being brought to a few industries with it beginning to trickle down into others. Government agencies, education, banking, and law firms were some of the early initiators that were paying more attention to ADA before any lawsuits approached their door.
The U.S. Department of Health and Human Services (HHS) also enforces Title II of the ADA relating to access to programs, services and activities receiving HHS federal financial assistance. This includes ensuring that people who are deaf or hard-of-hearing have access to sign language interpreters and other auxiliary aids in hospitals and clinics when needed for effective communication.

The ADA statute identifies who is a person with a disability, who has obligations under the ADA, general non-discrimination requirements and other basic obligations. It delegates fleshing out those obligations to federal agencies. The agencies issue regulations and design standards. The regulations have the details on the rights of people with disabilities and responsibilities of employers, state and local governments, transportation providers, businesses and non-profit organizations. The design standards specify how many entrances need to be accessible, how many toilet rooms and the design for those elements.  To know what the ADA requires, you need to read the law, regulations and design standards.