I don't see the $20 as reducing the barrels of chips you have in any meaningful way. Like others have said, this is just so that I can buy "only" 800 of the same denoms lol, and a rack of $25s can be more than a barrel each just to hold value and redistribute chips. Everyone still gets a rack of chips but when Tommy manages to lose a full rack, he can buy back in and I can use the value chips to represent way more.
10 is a little small for what's supposed to be a big chip, just half a barrel.