EIN is free. You can do all above, in less than 30 minutes.
Not to defend, atlas, or this or any other service, but if they act as an agent or offer a virtual address, they may be why the cost is high. You do need a physical office address, even if it's a virtual office, for service, and paperwork.
You should be able to find the agency/agency of incorporation for the state - https://corp.delaware.gov/howtoform/ this is for Delaware, and right there #2 is registered agent.
Depending who you go to for virtual office, it may be $50-200/month.
Now, is it a business idea to offer this service yourself, rent a space, and also have an accountant, - yes.
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But it's pretty cheap in general, other countries in the world, the cost of doing business for this meta/paperwork is double or triple.
In Indonesia, Doing a PT. PMA, sort of similar to a LLC, minimum setup cost is about $4000, but it nets you a visa.
Japan, requires $50,000 fiat, getting a hanko - and while it gets you a visa, is much more complicated.
They take advantage of people that have an initial negative reaction to doing anything that sounds "legal-y" but really all they are doing is submitting 2 forms (certificate of organization with the state, application for EIN with IRS), giving you some template document for an operating agreement, and then once a year filing a one-page form to keep the company in good standing. If you're paying more than $100 for this, you're being taken for a ride.