In the past I have used a company called Charles Hyde & Sons (aka CHS). They used to supply mechanical components, subassemblies (like laser assemblies) and PCBs for loads of AV equipment. e.g. I bought a power supply PCB for an LG DVD/HDD/Freeview unit for about 30.
I see that they have recently stopped trading.
I was wondering where else people go for this sort of stuff? The kind of stuff that's bespoke rather than electronic components?