Thankfully in Scotland the pay scales are determined nationally and there's no opportunity for HTs to just not pay people the right amount.
I don't think reintroducing prescription charges would help- it wouldn't raise nearly as much money as you think - in England over 90% of prescriptions are free of charge anyway due to exemptions, and the money goes to the NHS not Education.
The problem is multifaceted -
Teaching is not an attractive career any more - low pay when you qualify for someone with a degree and post-grad diploma. The working conditions are terrible. Zero respect from pupils or parents a lot of the time, or from the wider public - even though we are expected to be parents/social workers/nurses/childcare/counselors as well as teachers. It's pretty soul destroying to talk to a parent and say 'they just need to come in for one hour to complete this coursework or they can't pass the course' and be told 'I cant make the little fucker get out of bed, what do you want ME to do about it??' and then get slated because said child failed and it's somehow all my fault. Or a child getting sent home because they were ill and the parent throwing a packet of paracetamol out the window and refusing to let them in as 'I don't want to see that little shit til 3:30pm' (that's sadly a true story where the guidance teacher took the child home after the parent refused to collect them, child had a high temperature and had been throwing up. They spent the rest of the day sleeping in the school office.)
Every time there is a budget cut, services like education and social work are easy targets: reduce the number of PSAs, raise the class sizes, close special schools, close SEN/EBD bases, cut the money for things like jotters and folders and printing. Stop maintaining the buildings properly etc etc. They don't have the heart-tugging that jobs like nursing or fire & rescue has (but they save lives!) so people are generally less bothered about education (teaching kids to read and write pfft) and social work (also save lives but are evil according to the press and many of the public) cuts.
The governments need to justify their jobs by rewriting the whole curriculum every few years, usually along whatever 'initiative' is currently the 'in thing'. Then throwing it out (along with thousands of hours of work) and making teachers start from scratch. Those textbooks I bought last year are now useless as they updated the course content yet again (despite government promises not to), and by updated I mean removed huge chunks, added huge chunks of different stuff and totally changed how they were assessing it. It's at the point that the teachers who actually write the textbooks stopped bothering as no one would buy them knowing they would likely be obsolete within a year.
They changed the Higher courses in Scotland this year. The classes start in June. The course specifications were published at the end of September. Up til then we were largely guessing at what we should be teaching! Oh and we're still catching up with all the changes made to N5 last year (classes in June, course spec in October) and on top of that they have actually made some more changes to the N5 this year as well. Oh and they also totally rewrote the BGE benchmarks last year (S1-3 courses). But oddly did not change the N4 at all so now it doesn't actually fit anywhere...the units don't match, the assessments don't fit and many teachers are expected to teach classes that are mixed N4 and N5. I could go on but I'm boring myself now.
No wonder education is in a mess.