Our 3D printing service typically charges based off the models volume, surface area, and bounding box. We don't factor in the grams of material as a variable. These measurements are put into a formula that spits out a price based on which process and material is select. This makes generating a quote very quick and easy for the most part.
From Ankermake's website, they say the cost per gram of 3D printing can vary greatly depending on several factors, such as the type of 3D printer, the material used, the brand of material, and the supplier. On average, filament-based 3D printing materials like PLA cost between $0.02 and $0.10 per gram.