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.
mordante
So lets for arguments sake say I have my transport and DAC modded.

I did some browsing and it seems there are 3 major players for clock upgrades.
Trichord, Tentlabs and Audiocom So who is the best? Or are they all good?

As for the DAC Bigkidz suggested I have the power supply improved if I understand correctly. Any more suggestions for the DAC?

What else?
Look for a used Cary 303/300. Should be able to find one for less than $2,000 USD.
Thank you for all the replies. Out of curiousity, what does affect the sound more, the DAC or transport? I thought about replacing the DAC for a Audio Note 2.1 or something like that.
I have been looking at a USB DAC. A DAC that USB and coax and maybe spdif optical etc.

The best contenders so far are Audio Note and Pink Faun, maybe BMC as well. But what else do I need. A harddisk device I guess, something like a NAS then we need an interface and a DAC. My main problem is the interface. Should that be a laptap or something else. But I want something with decent size screen so I can browse my CD collection.