I'm the exact opposite. No reason to have thousands of dollars worth of machines, if you don't have an equal investment in the raw material. Just my philosophy.
Buy lumber when you see it, that appeals to you.
The hard thing is not finding a good deal, but finding quality lumber in my experience.Keep it on hand and don't buy in small quantities, or just enough for a project. If you need 20bd/ft, buy a hundred as long as it's good lumber.
When you're considering buying a small portable building to house your wood "stash", you're beginning to have enough.