Do prices fluctuate?

I'm trying to determine whether to sell or hold unused items. Only a few items sell for more than their crafting price. When crafting, do the creation and selling prices (in bells) ever change, or are these numbers static? (Similarly curious about the rotating marketplace item values.) Or do these costs fluctuate based on other factors?

Solution 1:

The prices and crafting material costs appear to be static.

This said, there's very little or nothing to gain from selling crafted items for a bells profit. There are a few items that sell for a bells profit, but factoring the cost of the materials, they're not worth farming. And multiple items are later reused to acquire new neighbors, so you won't want to sell or delete the crafted stuff you're not using.