Policy on Heb B vaccinations changed this year. Basically now medical schools own occupational health departments are either a.) supposed to do it themselves or b.) supposed to pay the £80-110 cost of it on your behalf.
At no point should you be giving your GP money to pay for those vaccinations, the medical school should be doing it. On the same note, according to policy your GP shouldn't really be doing it for you for free because that means your GPs occupational health is covering the costs but you arent going to work for them, which is quite cheeky.
Sadly medical schools are also being cheeky, still telling students to get the vaccinations done by their GPs and telling students they may have to pay. But don't worry, even if your school says this (mine did) and you turn up without the vaccination they won't mind. They'll do it for you. Now i'm laughing at all the students who paid practically a months spending money, or 3 text books, or 50 pints of beer getting vaccinations they could of had for free.