This hasn’t been true since the 70s. Back when the price of an item was dictated by things like material cost and labor.
My wife followed this influencer who was selling an $80 necklace. This influencer had sold hundreds of them. It was from her “personal” style collection. My wife was hoping to find something similar for cheaper so she reverse searched the necklace. She found the exact pendants and chain for sale for pennies. The $80 necklace cost my wife $5 to make, with shipping.
Cost is not an indicator of quality anymore. Things cost whatever the company thinks you’ll pay for them, and not a penny less.