Having used a number of bulk and better quality (Higher Priced) ammunition over the years I have not found that consistancy/accuracy is automaticly better when the price is higher. This last year I added another 9mm pistol to my collection and after putting 400-500 rounds through the gun found it much more accurate with metal cased bulk ammunition than a moderatly more expensive brass cased ammunition that cost me 6 cents a round more. I believe that the best approach is to try different grades of ammunition in a particular gun and see what is the most accurate. Sometimes "price" of the ammunition is not the deciding factor.
OP-Maybe it's just the way I am reading your wording, as your choice of words is a bit confusing, but is English your first language?