Since this airfield isn't open after 5 during the winter and only until 8 during the summer, there are very few who ever use them for night flying, especially as the gates are usually locked 30 seconds after the licence finishes. I've only used them once in 2 years and even then I had to fight to get them put on, even though I'd given notice 5 hours earlier that I'd be returning just after dark. My point isn't about landing at night, but if you ask for them during the day.
If the wx turns nasty and someone is having trouble finding the field, then having the lights on could be an enormous help. i.e safer.
If there is a charge to be made, this could introduce an element of doubt at the worst possible moment. If there are no lights, then so be it, but to charge extra for what could be a safety device is a bit over the top. To me this is exactly the same argument that is made about landing fee's and wx diverts and we all agree on that.
Do they cost more to run, yes of course, but the landing fees are already well over the top. Doubling it up to £20 a landing for a homebased machine is a bit steep. Especially since they are about as useful as the lights on my Christmas tree. As for the money spent on maintenance......... It only costs something if you do anything!