Ranch house, 1200 sq feet. Attic's loaded with pink batts. Roof's got 4 vents evenly spaced across the back of the house. No ice damming, not even a hint of it. In summer, even if it's 90+ outside, the AC runs maybe two hours while the sun's up, probably due (I assume) to three trees that provide shade in exactly the right places between sunrise & sunset.
Three roofers are suggesting a ridge vent and soffit vents. I'd rather conserve funds at the moment. Even though these accessories don't add a lot to the price, whattya think about leaving well enough alone?