$15k is nothing, that's average Joe kind of bribe money. I would pay $15k to have my kid admitted to a top university. That's less than $4k a year for a 4 year bachelor degree, compared with the tuition its peanuts.
I think many people could and would do this - if they saw the opportunity.
Embarrassing to be found out - and sent to jail. Kids ridiculed for being too dumb to make it on their own.
Not sure what this couple is worth - but are probably not anywhere near Brad Pitt. Many celebrities are not super rich.
I remember hearing what a professional athlete I admired got paid - he was in Tour De France and had the yellow jersey for a couple of days at one point. His 'take home' pay was less than a new graduate. Lived a spartan life in cheap hotel rooms, training and racing all the time.