Payback to Come: 525

I still have one dollar to pay back to W of the three I borrowed (see the other two here: Pennies and Inflation.) A few weeks ago he set up exactly how I would pay it back:
I could either count every digit on a handful of coins or every numeral on some dollar bills to get a total number. That number would be the number of slaps, whacks or smacks that I would have to endure in order to pay off my last dollar.  So a coin that has 1995 on it for the date would equal 24.  A dollar bill has all kinds of numerals on it, including long serial numbers, which might add up to more (or less.)
The kicker? I had to choose coins or bills before adding each of them up.
Still, it seemed an easy choice. “Coins,” I said, without hesitation.
W raised his eyebrows. “Are you sure?” he asked, and went on to explain again how it would work.
When I nodded emphatically that I was absolutely 100% sure, he handed me one coin and one dollar bill and insisted I look at them both. I couldn’t decide if he was trying to save me or trick me.

But no…even after looking at them both, I was really really sure that I had made the right decision.
“Okay,” he said, his tone one of finality – and doom. He knew I had made the wrong one.
He handed me three one dollar bills and a handful of coins that added up to three dollars.

“Add them both up,” he said.  So I did.

And that, my friends, is the number. 
Five hundred and twenty-five!
He just said, “Time for payback.”
I’ll be back when I’ve paid him back.  If I can still stand up – or sit down.