Earlier quoted context omitted.
What exactly is stopping you from investing $5000 in your friend's startup?
Presumably Rule 506(b) which prevents fundraising from nonaccredited investors. There is an exception for up to 35 non-accredited investors but taking money from even one non-accredited investor greatly increases the disclosure requirements on your startup. So the startup would essential need to do disclosure as though it were a public company. https://www.sec.gov/smallbusiness/exemptofferings/rule506b
You absolutely don't need to do disclosure like a public company if you have non-accredited investors.