> it doesn't look like it would cost more than $1,000 for LLC, EIN, and the legal legwork. Maybe $500 more for trademarks through the post office. Am I majorly missing something here? I wanted to solidify our company asap to secure names, social media profiles, domains

sure, sounds ok. But that isn't "starting a business", that is just doing some paperwork.

If you want to do that stuff, then by all means go ahead, get a domain name, register an LLC. etc.