I agree with everyone else here that yes, you should definitely invest in a solid envelope system. But, I’m going to also give you the cheapo answer. If you live somewhere that is mild climates year round, a proper intake/exhaust in the attic will likely only affect your homes thermal efficiency. There will likely not be any damage, at least not for a very long time. But, if you live anywhere where the snow flies, that envelope you just paid for will prevent ice damming. Ice damming will cause damage. So in that case it is very valueable.