Yes. It was a badly titled submission. The TC headline is 'Tesla buys $1.5B in bitcoin'

Bitcoin production is capped at 21 million BTC.

More like 150k. You don't pay anywhere near retail when you buy in that quantity.

A 75% discount? I'd bet less, in the 20-30% range.

Who is going to sell at a huge discount and why?

Big miners who would otherwise need to sell it for USDT. Instead they get Elon to create an American shell company for them to get their money out of China or wherever.