There are prices for everything out there, maybe not directly on clearweb or darkweb, but you can find manufacturers and use your imagination how to get the prices from them in bulk.
It's very simple, and it is all about work experience. Let's take a cup of coffe for instance at a cafe.
The price on the exact same cup of coffe does not only depend on the coffe beans, but also the purchase cost, staff cost, rent cost, maintianance cost and many more factors.
Switzerland:
Rent: 10$
Staff: 10$
Coffe beans: 10$
Maintainance: 10$
Price for a cup of coffe: 3$
China:
Rent: 7$
Staff: 7$
Coffe beans: 7$
Maintainance: 7$
Price for a cup of coffe: 1.5$
The price may differ between the two of these but the quality of the coffe is exactly the same, because each country is driven by their inflation and world inflation. This is a very simplified example for you, but I hope you understand my point.
Best Regards