"A figure so high goes beyond fair and unreasonable and starts to become a punative penalty charge, which is unenforceable in contract law."
Punitive penalty charges are related to breaches of contract - i.e. you can't say "you will give me your pencil, or if you fail to do so, you will owe me £38,000". There is a long-standing principle that courts won't apply any sort of 'value' test to contracts. The only validity check they'll do on payments is to query whether the contract seeks to exchange the sort of thing that contracts may concern.
If it was otherwise then the courts would effectively act to prevent people getting bargains, and some very specialist forms of contract such as futures and forwards might become unenforceable.
Concerning the actual article, this man is clearly an idiot since if he'd applied any intelligence whatsoever then he should have been able to deduce the probability of high costs given the knowledge he must have acquired through his profession.