Roughly what you would get in the mob for similar levels of SQEPness for a Flt Lt (so £60k-£70k max). However, there are advantages and disadvantages. You obviously get geographic stability, you don’t get OOA detachments and the Ascent contract is long so there is job security. If you have pension or EDP to be paid it won’t be abated and paid in full on top of the salary. But you don’t get to move around (some folks like the variation and choice of mil life), you only get a 6% contribution to your pension (mil pensions are effectively free and are worth about 60% of your main pay - so if you earn £50k main pay (pensionable) and £20k RRP (non-pensionable), then the Armed Forces Pension is worth an extra £30k per year which would soak up most of any immediate pension/EDP pay outs), to start with you only get 25 days plus 8 BHs (33 days - whereas HMForces get 38 days) and the death in service benefits are not as good.
Horses for courses really but you are still a part of the Whole Force and so helping with the Defence effort. So not all bad.