You're looking at that the wrong way, pin-smasher -- the company's actual cost to produce a product has very little bearing on how much the customer pays for it. The final price of a product is partially based on the costs involved in designing, creating, transporting, and so forth, but it's mostly based on what someone's willing to pay for it. If they charge a higher price and sell fewer balls but make a greater total profit than selling cheap for volume, that's probably their best option. And pricing is also dictated by how you want to present your product. If you advertise an Invasion as being a super duper strong monster, but it costs the same as an entry-level Tropical Storm, that's sending a mixed message to the customer.
Long story short: it's not bull. It's just basic marketing and economics.