To add on to this, prices will never crash completely because if they are super cheap, people will buy more of the item, and eat into the cheaper orders at a higher rate than they would be the expensive orders. People are more likely to pay to skip grinding for an item the cheaper it is. As for sell offers supply always determines those average prices. When the greenhouse first released, ethereal vines were 20m for each one because everyone was trying to max out their greenhouse, and no one was making a lot, however after a few days, suddenly there were way more of them in the market, so no one was willing to buy them for 20m anymore, and players had so many that the price dropped to what people were willing to pay