We do that, too. For example, one of those Redditors owns 22,612 BRK.B shares and has been buying since late 2002.

Berkshire spent $25 billion in 2020 (all of its operating earnings) on buybacks at an average price of $205 per BRK.B share. That buying continued at almost the same pace in 2021 and the average price paid is $220 per BRK.B share.

We can't buy at that buyback price today, but many of us would gladly pay, say, $250 per share for BRK.B.

Yeah, but what kind of fool would sell BRK.B at $220 in 2021, when you can sell it for more on the stock market?