Jeff, Albert and Stringreen offer excellent perspectives with which I concur. The challenge in answering your question is that the answer will be different for each of us depending on our listening priorities. Like Albert, I prefer listening to vinyl. I've listened to a lot of high end digital, but I continue to stay with vinyl as my preferred source.
Ultimately, the only way to answer your first question is with your own ears after listening to some systems that have been set up well for playing vinyl. That will not be most dealer setups, unfortunately.
To take a stab at an answer that I think is at least directionally correct: To match or exceed good high end digital these days, my experience suggests you should plan to spend as much on the vinyl playback as you have on the digital playback. Plan on investing something north of $10,000 for turntable, tonearm, cartridge and phono stage. Less or more will depend on how much the strong points of vinyl resonate with your listening priorities. (For me, the match point will be less because of my listening priorities.)
To address your second question: In my experience, "bad" LPs are not better than good CDs. OTOH, good LPs are common and their sonic virtues easily exceed those of the same recording released on CD. The quality of LPs is indeed variable, but the same is true of CDs. For both LPs and CDs, the quality of the work done by the original recording engineer, the mastering engineer and the pressing plant all impact the sonic merits of the finished product. If one shifts to listening to some of the 45 rpm vinyl reissues available (the 45 rpm jazz reissues from Analogue Productions and Music Matters, for example), I'm hearing about as close to master tape reproduction as I think I'm ever likely to experience. For an interesting discussion of this topic, read the comments from mastering engineer Steve Hoffman about his experiments when he had the "Waltz for Debby" master tape in house:
What sounds just like the master tape: CD, Vinyl, SACD or an Open Reel tape copy?.