The beasters in the bag weigh 12 grams. "One and a half quarters" is 10.5 grams. So what is in the bag is about 1.5 grams more than what you are buying.
http://forum.grasscity.com/recreatio...s-hashish.html
Now, to follow this up. Everything type of herb you buy is going to have different densities. Thus, every time you buy herb, it may weight exactly the same, but look completely different to you eyes. This is why it is vital as an herb smoker to obtain a quality, reliable digital scale. Go to ebay or your local headshop.
If you are ripped off for $10 in herb for every 10.5 grams you buy, it only takes being ripped off two or three times before you could have bought your own scale, and saved all that money (essentially making the scale pay for itself).
You should always protect yourself against people who inevitably will try to rip you off.