How To Spend $2500 on Analog Setup


I currently own a Thorens TD321 with a Sumiko arm and a Goldring cartridge. My phono pre-amp is a Monolithic PS-2 with the MC-1b power supply. Over the past 6 months I have returned to vinyl and would like to upgrade my set up. I listen to mostly rock and jazz and enjoy the live sound. The rest of my setup is Vandersteen 3A sigs, Aragon 8008x3 with an Aragon Soundstage.

If I was going to spend $2500 would I 1) get a new turntable; 2) get a new cartridge; 3) both; 4) neither?

I am open to used equipment, but I have never purchased a used cartridge.
dminches
With respect to isolation, the Thorens is currently resting on a salamander triple bay stand. The stand itself sits on carpet on top of a concrete slab.

What forms of isolation would you recommend? Also, what cartidges should I consider?
I second Jaybo's response. I would add that the table can be tweaked if you must, with vibration isolation of your choice. I totally agree that the cartridge plays a tremendous role in the type of sound you ultimately get. I have been told that buying a used cartride is a very bad choice simply that unlike other gear cartridges are more delicate and absolutely must be used correctly, by vinylphile friends. I realize that any gear can be ruined by abuse but cartridges are more prone to suffer from minor deviations. So keep yor rig and audition cartridges.
keep the turntable...there's nothing close (new)with an arm at 2.5k........get a new cartridge and more records