Survival's economy is fully managed by the members of the community. Given how you are the ones responsible for setting up the prices on the auctionhouse and your own shops. Therefore, it is up to the overall market to determine whether your item is worthy of being sold/purchased, or not.
Within this page, we will provide useful information regarding the player shops and the auctionhouse.
Unlike the player shops, the /auctionhouse has a much higher diversity of items and especially
prices. Given how the player shops have overall less attention, and are less accessible than the auctionhouse. But, it
is due to this that the prices within the auctionhouse are also more diverse, and it is due to the amount of players
wanting to sell the same specific item.
Throughout time, the items can either gain or lose value. This mainly depends on their rarity and difficulty to be obtained. For example, a netherite ingot could be worth dozens of thousands of dollars at the beginning of the season, and eventually go down by some thousands by mid-season.
The player shops are overall an interesting feature. It allows every single player to advertise their items, but at their own location as well! Meaning that a player can build their own store inside their claims, and place multiple different items, resources, or minerals for sale or for purchase. Surely this is the major difference between the player shops and the auctionhouse, given how it could take some extra tiem to locate the right player shop.
Nevertheless, once you have stablished the shop you'll be using, everything will be much smoother!
NOTE: Compare the prices of the items a player is selling to someone else's store, or ask around the chat, this way you will be able to have a better understanding on whether it is worth it to sell or buy the item for that price.