That is an interesting statement. In order to determine that, you'd have to know the retail conversion rate of all existing inventory, and value of all equipment, average sales, then an estimate of all IP.
I haven't worked a full time job for 15 years, I currently work outside Binder Design only four days per month as a technical adviser. We've supported a family of four people, sent two daughters to a private university, and I own two homes, one that I paid cash for. All from Binder Design money.
But if you've never run a business and have certain ideas about what it is like, it's not like that.
It is hard work and not for everyone. I would not leave a good paying job for it, but it is a perfect fit for someone who is nearing retirement and wants to keep going and work from home. For $75K you get income for life if you want it.
While I'm not going to discuss actual annual sales, I will say this: Just one kit like the Velociraptor has grossed well over $100K since it's release.
So if you have to question it, it is probably not the right fit for you.