The person who wrote the article is a journalist, not a lawyer so they don't understand contracts.
The Mizzou AD was on the radio this morning here in KC and explained buyouts in a coaches contract. The buyout is only = the amount of base salary time X years. For Mike Anderson, who was making almost 2 million per year, his base salary of that 2 million (base is defined as that portion paid by the institution) was $275K. The contract MU was owed that amount times 2 years for a buyout, which equals 550K that Arkansas owes MU.
I would guess we would owe Marquette around the same amount, but probably less.
i'm not sure there is any "normal" or "standard". the buyout can be anything from the entire amount of the contract (i.e. no buyout) to nothing.
i've also seen it stated that the amount the school owes a coach, if fired is the same as the amount the coach owes a school, if he leaves. which is also not necessarily true.