if you had my system and $2,000 budgeted for an upgrade, where would you spend it?

This post may go a bit beyond analog, as it could encompass other parts of the system, but I am not interested in adding to the digital side of things, so here it is.

As far as I can tell, it seems like the places to spend that $2K would be on a better tonearm or perhaps a preamplifier upgrade.  I may be able to sell my Audio Research LS-25 and upgrade to ARC Ref 3.  As for the tonearm, I could sell the RB202 and get a Michell Tecnoarm, or step it up to an arm for about $1600 (are the Clearaudio arms nice?) and still have a little left over.

Can a tonearm upgrade make a significant sonic improvement?

I am not dying to spend money on an upgrade, and if the benefit of that $2K will be minuscule, I am happy to stay as I am for a while, my system sounds excellent.  But I am curious to know what the experienced people on this site would do the the $2K if they were in my shoes.

Where is the most improvement possible?
Thanks!
Mark

System Gear List:

Amplifier:  Audio Research VT-100 mkII
Preamplifier:  Audio Research LS-25
Phono Stage:  Whest Audio PS.30R
Cartridge:  Lyra Delos
Table:  Michell Engineering Tecnodec with standard RB202 tonearm
DAC:  PS Audio PerfectWave DAC mkII
Power Conditioner:  Shunyata Research Talos
Speakers:  Rockport Technologies Mira Monitors
Subwoofer:  Wisdom Audio SCS
Speaker Cable:  Cardas Audio Cross
Interconnect:  Cardas Audio 300B Microtwin XLR
Digital Music Storage & Player:  Apple Mac Mini + ROON + Hard Drive
Power Cables:  Shunyata Research Venom HC (amp, sub, conditioner)
Power Cables:  Shunyata Research Sidewinder VTX (sources)

My system can be seen here:  https://systems.audiogon.com/systems/5421