They’re not writing big checks. I have a self-directed IRA, for example, with about 100k in it. Not a heck of a lot of money, but my paper wealth in the form of founder’s shares of my last, still pre-IPO startup makes me an accredited investor, but self-dealing laws make me legally obligated to not use that money on my own ventures. So I can cut checks in the order of $5k - $20k, and do that 5-20 times before I run out. It’s fun, and I get investor updates from companies I really want to see succeed.