Costco is a bulk retailer that charges membership fees to access their stores. Hasbro is a manufacturer of products. I'm sorry you don't understand why they're significantly different. Good luck. Even the most popular normie tier kits are hard to get your hands on right now. Bandai has been unable to keep up with the higher demand. The pandemic has significantly reduced the output of their factories and Gunpla is being scalped hard. You could all look into Robot Damashii Action figures, the thing that's actually comparable to Transformers and see what high priced collectables actually go for.