Lots of factors influence the price of a good!
However, to name a few and their influence;
-The demand of a good determines the price. If a lot of people are wanting a certain good, then the price will rise because the item may be purchased out of stock more quickly.
-The cost of making the good determines the price. For example, if a cake is made with cheap ingredients bought in bulk, the price will likely be lower than the price of a cake made with high-quality ingredients that are only available in small portions.
-The amount of the product determines the price. This kind of ties into demand, but if there's only five of a product available for sale, it's likely that the price will be raised significantly so that they don't all sell out immediately.
-The region/area determines the price. The best example I can think of for this is an ice cream shop opening up in a freezing-cold town. A hot chocolate shop will likely sell more products in this environment. Because of that, the hot chocolate vendors can sell a higher price because the product is more ideal for the area, while the ice cream shop will likely have to lower their prices.
I'm sure there's more, but these are just a few!
Hope this helped! :)