Truth is you can get the same kind of pricing structure with window cleaning. We've all seen the kind of thing £5.00 a house, £2.00 a front.
It's okay. There's plenty of work out there. Do a good job, fill your books with recommendations, advertise in the right place, have a nicely presented professional website. Uniform, polite, paperwork.
Let the bottom feeders do there thing, you don't have to work at their level even if you feel the invite is obligatory.