The cottage industry that is student dealing flourished around 2008; partly as a result of a decline in academic values within many British universities and partly due to the arrival of the student-favoured cheap stimulant mephedrone.
By 2009, reports began to surface claiming that some people actually enrol on university courses with the sole purpose of selling drugs — the student loan serves nicely as a start-up fund. By 2014, I think everyone had to admit that casual dealing amongst students had become commonplace.