I totally agree, it would be great to have a Wiki or library with general/basic flows that users could copy or build on. But I suspect the reason this doesn’t exist is because flows (especially Advanced Flows) are so customizable that it’s hard to make examples that fit all setups.
That said, there are a few useful threads and resources:
The Flow Exchange Thread — where users share flows and ideas.
Homey Support - Flow Examples — basic flows and guides from the official support pages.
You can also find great inspiration by searching the forum using the Flows or advancedflow tags.
Yes, combining power usage and hourly prices makes the flow much more efficient and cost-saving 
Here are a few ways to integrate price into your flows:
Use the recently released Homey Energy flowcards as example:
“It is one of the x Hours cheapest hours of today”
You can use this to run a flow that only starts EV charging or heating when the price is in the cheapest of example 12 out of 24 hours.
Homey Energy Flowcards:
Strømregning App (Link)
This app doesn’t yet offer flow cards for the cheapest hours, like the other apps does. But it does include cards for average/median price, which can work for simpler setups.
Example use:
“And” Flowcards:
Tibber App (Link)
Tibber has powerful flow cards for price-based logic (if you are a Tibber customer).
Power by the Hour App (Link)
If you don’t have Tibber, the Power by the Hour app is a great alternative. It includes similar price flow cards like Tibber.
Heating Controller (Link)
Heating Controller have also the similar flowcards like the other apps.
