That all said, maybe the ideal would be to just trigger on a small increase (fuel has started to go up) and have some form of hysteresis to stop a barrage of notifications…?
My 2cts, would create a automation where I trigger on state-change
Add a if/then condition/action where I check on the difference between trigger.from_state.state and trigger.to_state.state. … if diff larger then XYZ, do something, else nothing
The downside of this is that the price could go up a large amount via number of smaller jumps.
Background
Here is Australia fuel “cycles” up and down - it used to cycle weekly - Tuesday being the cheapest. Now it is more sensitive to regional and global supply and demand, but even now, there is a weekly cycle. So the trick is to try fill before the uptick.