One thing that is often overlooked are the benefits in staff positions. granted, at part-time, there won't be the same benefits that a full time position would have, although I'm not sure about how UK gov't jobs would work. I am in a staff photo position and started actually as a part-timer. I worked two and a half days a week, as a lab tech and assitant to a studio photographer. At the time, the amount of money I earned--I was in my early 20s--seemed pretty good, since I had barely eaked out a living in the year before trying to work as a freelancer. I worked for a little more than a year as a temp--first working the two & half days, then eventually working 40 a week. I never worked OT during that stint as a temp--not like I would later do as a full timer, only here's the deal--when I work OT, I get time and a half, with premium for holidays--this is double time. I get paid or get it in comp. I now have 16 years as a staffer more or less, 15 of them officially.
How this works out--I started near the bottom of the pay range, and each year got COLA & pay raises. I moved to the upper middle of the pay grade this way, only to be reclassified in a national type survey of commercial photog jobs--I moved about 3 grades higher, and got a bit of raise this way, as the salary was adjusted. Every five years, I incrementally move higher in terms of how much paid vacation I get. I earn about two days a month right now. I have close to 300 hours of paid vacation alone now, and close to 1000 hours of paid sick leave. I can carry 200 of those vacation hours indefinitely and all the sick leave--apply all that towards retirement as well. When I made 5 years, I became vested. When I hit ten years, I started to get longevity pay. I get full major medical paid for by the employer, and cover my wife under it as well. There's a good retirement plan, and I will be able to retire with a full pension--sometime in my early 50s.
All my gear is supplied, facilities (2 darkrooms, studio, finishing areas, computers etc). We have a car, and access to a motor pool for vans, trucks etc. Fleet cards, access to fuel pumps at gov't facilities etc. When we travel, we get per diem--food & lodging covered. Our equipment insurance is covered, liability insurance is covered etc. Basically everything you would get as an employee. This is what I would look at in terms of reading job postings like this. The benefits on top of the salary, as well as the facilities & what is supplied. It all adds up in the end. What you bring is the skill as the photographer or whatever the job requires--they supply the rest. That's why in terms of work-for-hire, they keep what you produce as well. To think of it as "yours" in terms of rights, is missing the point. That is the tradeoff for the paycheck & the job security. For me, it has worked out well, and I can't complain.
my opinions only/not my employers.