Even if you're taking a purely financial / economic approach*, it is very hard to second guess what is and isn't a good idea. Who would have guessed in 1950 that being a pure mathematician or a logical philosopher would be potentially extremely lucrative 10 years later.
Also, I don't know what people mean by 'a vocational degree', but if you look at degrees and what people end up doing, it is hard to see the point in doing something with a 'career' attached - only something like 25% of law students become lawyers, many engineers don't become engineers, probably the majority of traditional science graduates (physics, biology, chemistry etc.) from good universities don't end up in science related jobs, teaching, some teaching jobs are massively hard to get (I understand primary is a nightmare) and then even once people are qualified a massive drop-out rate into other careers, and I'm sure the same is true of most courses. People just don't follow that perfect well defined career path all the time. I don't know the figures for medicine, but I know they limit numbers quite strongly, so I suspect if you complete the course you are very likely to stay in medicine, maybe that is the odd one out.
I would worry more about taking a too vocational course, that it might limit you, in that you don't learn much about general stuff, so if you can't get the exact job, you're screwed. I've certainly heard that said about 'computer games development' degrees, both people in industry and people teaching the courses have said to me that kids would be better off doing a computer science degree if they want to develop games.
Oh, and I would do it again, but then I have a job which I really couldn't do without a degree or two.
* Which you obviously shouldn't, you should think, what am I interested in, and study something you're interested in, and aim to do well at it. No point having a useless 3rd in something sensible when you would be excited by Medieval French enough to get a 1st in it.