CD player how much to invest

I sometimes wonder should I invest more in digital playback in the future. My current CD transport is a CEC TL51x with a Wadia 12 DAC.
From shows and visits to friends I have learned that there are better CD players out there then my combo, but at what price. The AMR CD-777, is a little better but at €4000 twice the cost. The AMR CD-77 and Nagra CDP are even better still but they cost 10 times or more then my combo.

But is it worth the investment even if I had the money. I believe that with say €2000 you can buy a good CD player That is maybe 90% of a €10.000 CD player.

However I do think that speakers and turntables have a higher return on investment sonic wise. A friend of mine will bring his Jadi Symphonia with Electraglide powercord + Harmonic Tech Magic Link I interlink. To compare. I somehow doubt it will be much better, it may be different but better I don't know.

I am wrong to think that? Are more expesive CD player really a lot better then mid priced and if so how come?

Sorry for my rant, but when I was thinking about upgrading my set and maybe buy an other CD player would it be worth the money? Will I hear a difference etc.