Can cl (in Britain) be commodified?

It has been a while since I studied Sociology, but it has been my understanding that the cl structure in the UK, back in the day was rigid and that social mobility was immobile. People remained in their own economic groups, and if they gained qualifications it would be to still ‘serve’ but to remain in that group. Given that Kate Middleton and her siblings had expensive education and went to a University that is patronized by the Upper cles, can we ume that we now live in an age where cl can now be bought?