The films
Most of the price is raw material. Each film has its own price per kg, and foil and BOPA cost more than PET, BOPP, or LDPE. Thicker films and more layers add weight and cost, so the cheapest structure is the thinnest one that still protects the product.
Printing and cylinders
Gravure printing uses one engraved cylinder per colour. Cylinders are a one-time cost per design, so an 8-colour design costs more to set up than a 4-colour one. Repeat orders of the same artwork reuse the cylinders.
Every run also wastes some material while the press and laminator are set up. That fixed cost is why printed packaging has a minimum order: spread over a small quantity it makes each kg expensive.
Format and finishing
Rolls are the most economical format. Converting into pouches adds cost, and features such as zips, tear notches, hang holes, windows, and matte varnish add a little more each.
What to send for an accurate quote
Send the product you're packing, the structure if you know it (or the shelf life you need), roll width or pouch size, number of print colours, format, and monthly volume. A complete spec gets a firm price; a partial one gets a range.