Money, unless it is Money as Debt, actually has no "cost".

The cost of Credit is the shared cost of administration, and the shared costs of defaults.

This has nothing whatever to do with arbitrary rates of interest.

Likewise the cost of Capital has nothing to do with interest rates unless you are in an economy where Money is debt.

The cost of Capital relates to the "market price" and that has declined from 25% pa in Babylonian times, through 10% pa in medieval times to around 5% pa at the Indutsrial Revolution. Now the world is awash in productive capital, and the streams of use value they generate, I reckon the market price can be little over 1%.

All of these in real terms, of course, since without deficit-based money there was little inflation historically, and there would have been little inflation in the last 100 years, I suspect.

The sort of rate Wessex Water got on their 50 year index-linked borrowing ie 1.49% pa is indicative, I suspect.

What you are able to "charge" for credit you create is pretty much constrained, I think.

There's a lot of stupidly high expectations out there for sure.