lethargic_man | Bespoke compilation CDs

In the wake of

livredor's question as to where one can get legal protection-free mp3s, I have a similar question:

Like

synergetic, I had a misspent youth acquiring tracks by dodgy means; but am now buying back legal copies of everything. I'm 95% of the way through buying back my album collection, and seven tenths of the way through buying back individual tracks, but, having bought back all the easy-to-gets, I've got to the point where I can't find compilation CDs any longer with enough tracks I'm interested in on to justify buying them. (I'd like to stick to £1 a track, though I'm prepared to stretch that to £2 depending on the track.)

So, my question is: Is there somewhere where one can order bespoke compilation CDs (i.e. of pretty much any moderately-well known track that has ever been available on CD)? Again, the same restrictions apply in re legality. I once did come across a service that was offering something like this, but they only had a couple of thousand tracks or so; i.e. recent chart music, which was insufficient for what I was after.