You can get dynamic contracts based on the day ahead price in Germany. You pay a negative price for the electricity there. You still have to pay a transmission fee and taxes, so the actual end price is almost never negative though.
Of course sometimes you also pay much more than normal contracts.
Also without merit order, you'd still pay close to the most expensive source on the spot market. It's a consequence of the open grid where demand and supply has to match and price is not fixed.
> The high consumer prices for electricity in Germany are a result of grid fees
Grid fees are a coverall for "making sure the whole thing runs", which in my mind covers "making sure there's gas (at least that's what we use in the UK) to cover the shortfall when it's not windy". The Gas stations need to be able to spin up to handle the demand, so it's an abritrage where you really want to maximise the amount of wind you use, while paying as little overhead to keep the gas ready to go. It's like being on-call, and having your on-call pay amortized into your regular pay.