Buying lumber has always been a lottery unless you plan on spending a fortune on really good reliable hardwood lumber. I was never able to afford that.
So I worked like every rough carpenter I learned from you use everything you can get your hands on and use your skill, experience and imagination to make it work. If I start with a load of lumber, I'll separate everything between good, bad and terrible piles. Terrible stuff gets immediately hacked to small support pieces, bad stuff is hidden in places where imperfections won't be noticed and the good stuff gets placed in critical locations where obvious flats and straight surfaces are needed. Anything bad or terrible also becomes temporary supports or scaffolding, then for me, it gets chopped into small pieces and burned for camping or used for warmth in the winter .... good dried lumber is excellent fire starter or a fuel for fast burning to warm up a cold or frozen cottage.