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

My experience with live recordings using a Tandberg 310 back in the early 1980s with chrome? Sony and TDK top cassettes had really low noise/hiss levels without Dolby.  I have transferred my recordings to CD using a Alesis Masterlink and they play back similar to a well mastered LP to CD.  Unfortunately, the deck was problematic and I switched to a Nakamichi ZX-7 which wasn't as low noise without Dolby.  I really don't like Dolby B cassette sound.  I think I'd rather hear a highest res 320 khz MP3. 

My own system is modest but surprisingly satisfying for me in my quest of sound quality... And experience had lead me to observe that NO audio system at any price sound the same in different room, and that room treatment can make differences in a room that are way bigger that any change of gear, be it a TT or a Dac… I will not even speak of vibration controls, or electromagnetic grid treatment of the house...I read all this thread and many arguments coming from all side are somewhat astute, sound or interestingly thoughtful... But the question of the OP is very difficult to answer in one way or another, without knowing, the room where his audio system will be, nor the way his electromagnetic house grid will be addressed, and which vibration controls methods will be used or not and I dont even speak about the particular hi-level quality gear involved...The level of hi-quality of vinyl and digital gear, side by side in an ascending scale, is one factor only, the room treatment, the vibration controls, and the treatment of the electro-magnetic grid of the house 3 other fundamental factors, and they are other important factors also ( like the source materials etc)… My best to all...

You are correct.  The room acoustics and power quality are paramount to maximizing the abilities of the electronics/speakers.  That's why I spent more on my room construction than on my audio equipment and it paid off.  See near the bottom of Page 2 of  https://forum.audiogon.com/discussions/the-5-stages-of-making-a-bad-audio-purchase?lastpage=true&page=3 my post for my detailed room construction details

Thanks Fleschler for the interesting link...

Not only conventional room treatment is paramount for sound quality, but the treatment of the electrical grid of the house and of the room, and some others unconventional treatment are paramount too for me : Schuman generators modified, Helmholtz resonators (homemade one), and other resonators of my own design (cheap homemade but with astounding results)…

Upgrading an amplifier or a dac, if you had already a good one or even speakers, before implementing these controls methods is for me throwing money without even knowing the real optimal sound of the audio system you already owns before upgrading it...Most audiophile change gear some months apart without addressing any of the fundamentals relatively cheap methods to improve in a stellar way their already very good audio system...

Beside that comparing digital sound and analog one in the abstract, or in a very particular system with a particular files or vinyl in a very particular room in a very particular house is for me without any value for anyone...Except for boasting about your taste or system... Basic problems first...I apologize for my rant and wish the best to all...

Room acoustics are extremely important but that avoids the question. Given the same room and system how much do you have to spend on digital to equal the performance of a $3K turntable. I do not know if that includes the cartridge and tonearm but say it does which means it is not a very high end table. It would be one of intermediate performance. You could probably beat it with a $2K computer and usb interface. That does not include the DAC but the turntable does not include the phono amp.