Cant remember who it was but i saw someone post a recipt from audi once for something like £3500 to have a DPF filter replaced and a bulb changed.
they took it to a garage who i belive either cleaned the filter or replaced it and then changed the bulb, ended up costing them around £500 iirc.

i only ever take my car to a dealers if i want a new part, from what iv seen from dealers is they replace things not fix them. if i want something fixing i buy the parts and take things apart and fix it my self