Upgrade my older Linn Sondek or move on?

If you have a local Linn dealer that is going to install the parts or you are a detailed oriented meticulous person and want to do it yourself I would do the upgrades. Each of the upgrades you propose will significantly increase the sound quality. I have a LP12 which I have upgraded several times and have been ver impressed with the cost effectiveness of the improvements. In the end, you can take the table as far as you want to contemporary Klimax if you choose. A really great feature of the line.

If you are neither of the above then sell it and buy a new table. It is not that Linns are finicky or incredibly complex any more, they are precision instruments that must be set up precisely. A friend of mine is a Linn certified master technician and tells me lots of stories of folks that set up their own table and put on the wrong nuts, or did not level the internal springs and wonder why it didn’t sound right. Anyway, if you are not a detailed oriented person, like me, there are lots of great tables available.

Couple of great upgrades are available for you with the LP12. Replace the bearing to the current Karousel and replace the arm...look for either a good used Ittok, or if funds allow...a used Ekos or Naim Aro. 

@ghdprentice The OP seems to have a c. $2k budget.

I have a few friends who have Belt Drive TT's, I have shared this info before.

One TT is a Brand that is modern, one TT is a older model from a Brand and modified with OL Parts and the other is a LP12 of similar vintage as your own having undergone some of the available upgrades (note Linn are not the only Company with Upgrades on offer for the TT).

The demo'/comparisons were far from perfect, as a result of using different Tonearms and Cartridges on each TT.

The outcome reported from the attendees was that there was not too much to be discovered, and the Linn was as attractive in use as any other being demo'd.

There might be discovered within the Link some info that inspires you to keep on with the Linn.

  https://www.diyaudio.com/community/threads/linn-sondek-diy-mods-that-work.272570/ 

@noromance  If I sell the Linn the budget will be $3.5k.
@ghdprentice No local Linn dealer. I would have to do the upgrades myself. Not completely opposed to doing it, however I would like as close to as little set up as possible.

@pindac thank you for the link