How much do you need to spend to get digital to rival analog?

Comparison's made with the same system cancel out everything except the variables being changed.

Except, how to escape the music being a variable itself when digital and analog are made from different (differently produced) masters? A fair comparison digital vs analog should include analog and digital sources made from the same master...

For digital it is relatively simple. It is all about the DAC. Any good transport will suffice. 

Possibly in a world of CD transports it's closer to reality; however there's comp audio, which is more interesting because of its openness to all the existing digital formats and resolutions...

rluciano - Similar to my system.  Phono-VPI TNT6 super platter, SDS speed control, tricked-out SME IV arm, Benz Ruby 3, Townsend Seismic Sink, Audio Interface SUT and custom made subminiature tube phono stage.  Cost over $22K plus cabling.  Digital = half that now that I purchased a separate DAC.  Still, great LPs sound great despite the 12 bit resolution asserted to by the other poster.

Yes zalive, it comes down to the master. But better is better. We have no control over which master is used. 
The question is, is computer audio better than digital playback from a CD drive. I can not really answer that question. I have compared the original CD to its copy on a computer (Apple Mini with Pure Audio) and I can not tell the difference and the computer is up sampling to 192/24 the player is not. A down loaded Hi Res version does usually sound better than it's CD counterpart but again are they using the same master? 
I am more than happy to get rid of all my CDs. They are now all on the hard drive, what a PITA that was. Gives me more room for records:) I have nothing bad to say about computer audio. I love the degree of flexibility you have with Pure Music which uses iTunes library to organize the music. The whole set up cost me about $5K. The Mini, a 6 TB hard drive and a Berkeley Alpha USB. This is about the price of my cheapest cartridge so from a price perspective digital has it all over analog. 
I only buy a CD on rare occasion when music I want is not available to download. 
Geoffkait with two F's, Michael Fremer's opinion is not one I would rely on. His hearing is way better than mine and your's for that matter. He can hear the "dramatic" difference between a $100K turntable and a $400K turntable. His use of superlatives boggles the mind. I can't even tell if he likes music. 
Geoffkait, I'm worried about your ears. Cassette tapes suck. I have a Nakamichi Dragon up in the attic you can buy from me if you like. I bought it to record cassettes for the car before CDs became available. 
I'll bet you are an 8 track fan!
Fleschler, I only have 2,348 78's  

Mijo
I will buy your Dragon.
It can join my zx7 and 660zx.
Cassettes suck?
What a preposterous blanket wet noodle statement but how come I am not surprised.
I invite you to an evening of cassette tape playback on my rig with some of my tapes.
Of course some tapes suck, just like some vinyl and some CDs etc etc.

I used a Tandberg 320? and a Nakamichi zx7 for recording live choirs in the 80s along with a Tandberg 9000 R2R.  The DAT deck was superior.  However, the cassettes I made were of superior quality to nearly all prerecorded tapes.  There lies the probable cause for the previous posts.  Prerecorded tapes generally were awful compared to LPs and R2R 2 track or 7.5 ips 4 track.  Premium cassettes recorded at home or live sounded good.  I got rid of about 500 cassettes and kept only my live recorded tapes. 

Mijostyn-good for you, another audiophile interested in the music first although 78s can be very dynamic if frequency rangebound.  They are direct discs with perfect non-edited take credentials.  My 78s go back to 1900 so stylus size, speed and equalization make it more cumbersome to listen to.  It's an active hobby to listen to acoustic 78s (pre-1925).