Interestingly I have felt the same way about looking at changing my career. I feel that for a long time we have been undervalued and now this definitely proves it.
I’m on a couple of locum groups where a few of us Locums as discussed with one another as to what to do and some of the locum optoms have done exactly what you suggested which is if they practice is only willing to offer £150, then they have reduced their hours to 4 hours.
It makes perfect sense. We all decided to try and stick together and not budge on this. We should not accept such low offers otherwise the rates may never go up once clinics are back to normal.