And I'm still mystified why there was no deal for Berkshire to easily be able to buyback shares from the foundations when they sell each year.

Price.

Berkshire retains the power to decide when and if shares are repurchased. Even for a thinly traded security, the range of market prices in any 12 month period is very large. In theory, the current set-up (no commitment to foundations or estates, but both can trade at will) allows the possibility of the sellers getting a good high price, and Berkshire's buybacks getting a good low price.

Since shares are fungible, if you like you can think of all the repurchases to date as having been bought from that sort of seller. It doesn't much matter if someone else held a specific share for a few months in between.

Of course, from a broader perspective, what does it matter? A share is only worth so much, and it will trade within broad spitting distance of that level no matter who owns it. It seems unlikely that Berkshire will buy back enough of the company, at a big enough discount to fair value, to matter much more than a few percent to the value of a share relative to important things like how the businesses are doing.

Jim