Cost alot,cheap air filters for automotive

We all look for the best price in day to day shopping.But the old saying,you pay for what you get is true,well,in this Item anyway.Buying the cheapest air filter for your vehicle is not always the best thing to do,what are we talking,4 dollars difference?Believe me,it is not worth the 4 dollar savings.Cheap air filters have to much resistance,and stop air flow.I found this out the hard way.In doing a complete tune up,I had made the car run worse than when I started,and it took me two days to discover what had happened.I had replaced the air filter with a filter of the same brand,and chose the cheaper grade that was offered by the same brand.Ah.I`ll save 4 dollars.Yeah,it was two sets of plugs later,a couple of sensors later,I discovered when I put the old air filter back in,by mistake,the engine ran perfect.So I switched the new filter back with the old one ,in the vehicle,and the engine ran terrible again.Threw a little research,I had found that the paper in the filter was a poor grade ,and had hardly no way for air to come threw it.Finding this out,looking deeper,and trying out different brands,of grades,the problem was real sensitive to some vehicles,and not so sensitive to most,but in all the vehicles,the fuel mileage went down ,along with performance using these cheaper air filters.So think about it when you purchase your next air filter.And as far as oil,and fuel filters,I would guess,if there is that much difference in the air filters,it most likely is true with these also,you just won`t catch it,until it`s too late.