Returns the current fee rates for the usual confirmation targets together with the state of the mempool behind them, and then does the part that is usually missing: it estimates the virtual size of the transaction you describe and computes the resulting total fee in satoshis for each target.

Day-ahead power prices for a European bidding zone from Energy-Charts, published by Fraunhofer ISE from Bundesnetzagentur SMARD data under CC BY 4.0 and therefore usable commercially with attribution. Returns the quarter-hourly or hourly curve with minimum, maximum, mean, the cheapest and the dearest hour, and how many intervals carry a negative price — the figures a load-shifting or battery decision actually turns on.