[rabidferret]

For purchases like the one in the article, you can absolutely purchase with stock in lieu of cash. This happens all the time, and doesn't have nearly the impact on the share price that selling for cash on the exchange does.

How much cash you could get in a vault isn't really a useful measure of wealth since cash isn't the only object of value that you can exchange for goods and services (which you even pointed out in your comment by mentioning gold)

[chadash]

Cash, or gold, artwork, whatever... Sure you can purchase with stock. But you can't easily purchase with $180 billion in stock without affecting the stock price.

[ascorbic]

If Musk started to sell off a significant chunk of stock he'd have to disclose this, and the stock price would take a hit whether it was on an exchange or for farmland.

[giantg2]

You still have to sell some to cover the real estate transfer taxes since the government doesn't accept stock. With a 1% transfer tax you're still looking at $1.7M. Not too bad though.