Vintage Dual 1228 Turntable : worth to upgrade cartridge ?

Even in restored condition the 1228 is simply not a great table.  Current demand is driven more by nostalgia than performance.  All classic Dual TT are well built, and durable.  But they are incapable of top flight performance.  They are not a Garrard, Rek-o-Kut or even a Lenco, nor where they designed to be so.

If your 1228 is in excellent condition, and has been serviced (as you state) then it is worth $200+.  Sell it and add the proceeds to your budget.

$1200-$1400 will buy you a used TT, new cartridge and new phono stage that will be an order of magnitude better than the 1228.   Rega, SOTA, AR, Thorens Tables are all within your budget.  Shure M97 cartridge with JICO stylus, Mid level AT or Goldring or Ortrofon with a new iFi phono stage and you will have a few dollars left for records !

I have significant experience with Dual TT.  I owned a 1229q Empire 2000 EEE combo for 12yrs.  I upgraded to a 721, which was an improvement, then to a Thorens TD318 which was a revelation and a significant upgrade from the 721.  I haven't looked back.   I currently use a AR ES1/ Shure M97he in my computer system, and a Linn LP12 ITTOKK LVII  AT33 MLOCC with Lundahl SUT in my main system; and both wipe the floor with a Dual.  

iopscri,

Thats completely ridiculous. I don't subscribe to audio snobbery as you obvious do. The age and cost of a component says nothing about its performance. 

I used to have a kilo buck LP12, so invested was I that I even bought the service jig so that when my dealer came down to install an upgrade, he didn't have to bring his. In the end and after a decade of upgrades we still couldn't get it to sound as good as a Dual 1229.

Here is what's wrong with the LP12. http://www.high-endaudio.com/RC-Linn.html

 Take time and read it. You'll find like me that many of what he experienced you probably do too. What Linn can do is market. What they can't do is build a turntable that sounds better than an idler driven table. Lenco, Garrard, Dual, Rek O Kut, E. M. T.,  one could go on and on. They're all superior. 

Norman 

Norman, 
the link on Linn LP12 given by you makes really some hard but very interesting reading for new anolog enthusiast like me . Also it is kind of eye opener demanding more neutral and realistic self assessment, of any audio gear for that matter , in future rather than be simply or solely driven by so called reviews . I did not know of this guy Arthur Salvatore , but he sure has lot to offer to audio community . 
Thanks for bringing up this here. 

 One other thing I did with my Dual and P+E was to clean all the headshell leads with aa toothpick and the tonearm contacts up in the arm first with Deoxit red and again the second time with Deoxit Gold contact conditioner.I used a toothpick to clean the clip leads that go into the cartridge and treat with Gold.I even took the stylus out of one of my cartridges and did the tube that goes into the body.I heard a difference as well as my entire system which I tuneup every few months with the Gold.

playpen,
 I have just done very similar cleaning only last night on my Dual . I took out the headshell , disconnected the 4 delicate wire leads from cartridge pins , Deoxit with N5 type first then with 100 % solution to clean all 4 pins of cart, and the 4 brass clips of lead wires ( I used thin paint brush to apply it within the tiny holes), left them overnight for chemical actions of corrosion removal. Now  since you mentioned , I will even clean with toothpick . It is kind a difficult to clean the inside surface  of  "clips" which is the real contact area.  Then apply Deoxit Gold with brush. I did not thought of cleaning the " stylus tube", but will sure clean it tonight before reassembling it tomorrow.