@Reiven Good god no. There has always been a huge problem with Pearl Abyss deciding the prices. They don't let supply and demand run it's course. There are items on the market that sell for such low amounts when they are worth significantly more but they are capped at the price by PA.
In regards to cash shop items they aren't properly rewarding people for the amount of money they are spending. This is probably why over the years they continued to jack up the prices they can be sold at and they'll probably continue to do it. This drives up sales for PA.
Nobody other than people with stupid amounts of disposable income are going to buy and sell the items when they give barely any in game currency vs the amount of money you are spending. This is why the value pack pre order is at like 4000+ from memory (probably higher now). That item is not worth selling at the current market price. Unless they balance the prices across the board that pre order will remain super high because any paying player looking to earn in game currency isn't going to sell the value pack. They will sell the items that give them the most return. I'm sure after they jacked up the prices pearl items could be sold at they probably started earning more money. It's really in their best interest to raise them as high as possible so more sales are generated from whales.