well, the most straight forward approach is removing the bumper, then removing the headlight assemblies to work on them at-ease, without potentially damaging yoru back or fingures.
so i think it's fair enough what they quoted - occupational health and safety at stake.
they probably quoted a couple hours work, which too is fair enough.
if you can do it for free, that's obviously a major bonus to you - so well done. but i do remove my bumper and light assemblies when i change the globes. there's no cursing and no cut fingers or aching back. it's not that difficult, so you could try that next time too.