Average wage?
Get a grip, they're not doing nine years on £9 an hour.
The system is broken and it's needed fixing for the past thirty years.
What's the point of paying someone £350 an hour and he disappears after eight years?
If he can get that in plenty of other countries then yes, pay him that, but if they're flocking here to work four years and retire then no.
Yes they do overtime through the method you mentioned, at an astronomical rate, so they do the bare minimum at regular NHS rates and then do the bulk of their hours at massively inflated rates.
It's common knowledge.
Also, there's other things going on, NHS worker, earning 40K can take voluntary redundancy and get 30k and carry on in the same job, same department, same boss and same hours, they're doing it in the thousands, been going on for years