I would not say 50 dollars for 1/8th is a good price, but it is a decent price around these parts (i know its sad). There are even some who will try to get you to pay $60! well what roll it up said is basically true but on average and eighth should fill up the bottom of a normal ziplock bag from end to end. or if you were to put your middle finger and ring finger together and then touch the tips of those fingers to your other middle finger and ring finger. If you see where I'm going with that. But yea there is no real possible way to just eye out and eighth perfectly, so get a scale.