I'm sure I've said this before but it's been a long time.
To me, the clear way to deal with it is to not care when cost-changing events or cost-changing ongoing effects actually start and stop. Rather, any time we care about what the cost of a card is, we start with the printed cost and then apply any applicable effects. It's fine to define an order for those effects, such as "cost increasers first" or "ongoing effects first", but the important thing is that we don't consider the calculated cost of a card to be a new baseline upon which future effects or calculations can be applied.
This is once again borrowing from the rules of MTG. In Magic, if you want to know a creature's power or toughness, you don't constantly track how a creature's power or toughness has changed over time as each new effect changes it. Rather, you always recalculate from scratch; starting with the printed numbers and then applying all the different effects in a defined order.
613.1. The values of an object’s characteristics are determined by starting with the actual object. For a card, that means the values of the characteristics printed on that card. For a token or a copy of a spell or card, that means the values of the characteristics defined by the effect that created it. Then all applicable continuous effects are applied in a series of layers in the following order:
The order then clarifies things such as how if an effect sets the power to a specific number, that happens before effects that just add 1 to the power.
This system deals well with the Fisherman issue; when your discard pile gets a card in it again, we don't just "undo" the Fishing Village effect. Rather, we recalculate from the beginning, and Fisherman's effect is no longer there.
All that being said, I prefer the route of simply never having cost increasers. The main thing that it does was already solved by Donald with the -

token. It causes issues with things like
Livery, and confusion such as this discussion. It requires an arbitrary rule about whether to apply increasers or decreasers first.