Upgrade Linn LP 12 or buy new table

What arm do you have? I would imagine the cartridge is in need of replacement. These are factors.

if you are interested in new, I am very impressed by the VPI Prime

I had a nicely set up LP12 and it sounded great, but I hit a point of either further obligation to Linn for upgrades and maintenance mor change. I decided to trade off on a Rega RP10. I do miss the musical pacing of the LP12, in my opinion it would become high maintenance and the trade off of, in my opinion, the freedom I felt I gained, the Rega has been a good transitional table for me. The timbre and pacing are very similar. But if you haven't been listening to vinyl for a while, you may not notice the differences in sounds of other tables by comparison.
if you have a dealer that knows how to tune an LP12 properly, it would be a lesser investment to start with. Then you have a way to see if you really want to get emerced  in vinyl. I think you will. If you do want it tuned properly contact Rick at audioalternative.com and get an estimate. You can ship it him and he ships it back set up as good as it can be tuned. 
This is tough decision if planning to spend 3-4K as that buys a nice table, but it also buys a good tune up, nice cartridge and maybe a good used phono stage if you need one. 
My final thought is have the table assessed by some one who knows them. After 17 years of sitting idle a lot of parts have dried and lost resilience and it may take a rebuild besides a tune up. 
Good luck

Why do you assume you have to spend 4K on upgrades.  The linn sounds very good without any of the new additions.  However, you will have to get it set up properly and you might need a few small parts like springs, which are cheap.  No matter what anybody says, once set up properly, a Linn does not require constant maintenance and it will stay set up for many years until requiring any adjustments. But you do need a good setup person.  

Assuming your arm is in good shape between a full tune up and a new cartridge, you can be back in to vinyl for a whole lot less than $3000. Depends on how much you want to spend on a cartridge!  Figure a Denon DL103, for instance, and your back in way under $1000. Dynavector offers some very good values too. 

• I apologize for not providing more details. The LP12 has an Ittok arm on it. I bought a Goldring Eroica LX cart.and a Jolida JD9 II phono preamp to use no matter what path I take. Since it's been a long time since I last played vinyl and the rest of my system is way beyond what I was listening to when I last played the Linn I figured some upgrade was due in the turntable. My present system consists of:

• Conrad Johnson CT5 preamp
  
• Velocce Saetta Amps
• Esoteric X03 SE CD player
• Focal Utopia Diablo speakers
• Focal Electra sub

.     Thanks so far for your help. Have a great day.   Henry