I agree with someone's assessment here that newstands are for completists, or for sellers who know their stuff.
Personally, I don't have unlimited funds to burn, so they don't appeal to me. I'd be happy enough to have a high quality first printing direct edition, then move on to my next book. As for variants, only if I like the cover or a fan of the artist. I consider myself a "practical" collector"
Having said that, I respect the zeal and tenacity of these completists. Good example is a post here I came across of a Superman 18 Doomsday from the first printing down to the DC newstands, very hardcore.