Are you asking us if it's foolish to spend $3K on a CDP? Just keep in mind that a price point is where the manufacturer stops adding any more value to something. If you take two identical boxes and fit them each with the same laser/transport, filter and DAC you can get two different sounding CDP's. Just use better transformers, filter caps, wiring/PCB's, output transistors and hardware. That one would cost more and (should) sound better. Will it sound good enough to justify the difference? That's where you come in to the equation.
I think what your friend is trying to convey is that the actual retrieval process hasn't changed over the years and the differences in parts and engineering are the polish. I happen to disagree - for what makes one CDP sound better than another is the same reason why one amp sounds better than another: power supply, voltage/current regulation and linear output devices. They cost big money as you move up the food chain and account for a large percentage of the overall cost. Add to that dampening, shielding and circuitry layout that minimizes signal path distortion and you get the idea.
I think what your friend is trying to convey is that the actual retrieval process hasn't changed over the years and the differences in parts and engineering are the polish. I happen to disagree - for what makes one CDP sound better than another is the same reason why one amp sounds better than another: power supply, voltage/current regulation and linear output devices. They cost big money as you move up the food chain and account for a large percentage of the overall cost. Add to that dampening, shielding and circuitry layout that minimizes signal path distortion and you get the idea.