Speaking as a teen who has pretty much picked up everytime he's left his house to see some mates this summer i answer your question fully to the best of my ability.....

I don't honestly know, i know i've somehow spent several hundred quid on weed this summer alone since the end of college but i ain't got no job or any money incoming, i may as well be seen as that stoner bloke who does really low level jobs every now and then.

It seems to just be a natural skill of teens nowadays to get weed, hell if i get desperate enough i end up doing a paper round just to make my wake and bakes that much sweeter (Early morning air, silence, birds chirping.... and boregore/ pink floyd/ Rush blaring)

But what most people i know in college usually do is put the money they get form EMA or whatever government scheme into their weed. Beyond that it just seems to be a skill taht they learnt from being extremely stoned around hobo's... granting them ninja hobo money making skills i tells ya.