Thought about one but not that seriously. My intention is to buy a Mac Mini (using the uncompressed option on iTunes) and a large hard drive which would be far more flexible (e.g. you can stream them all over the house) but possibly a little more expensive.

The problem as I see it is that if you have several hundred CDs you need somewhere to store them, in a retrievable form, adjacent to where you intend to play them. A decent CD cabinet - rather than a set of racks from IKEA - will cost you over £1000; hence it would be simpler to commit the CDs to a hard drive and store them elsewhere.