First in line...

At the moment I can't afford to upgrade both so which is best to upgrade first, arm or cartridge...?

I'm currently using an upgraded Origin Live Onyx/Audio Technica AT33EV & Roksan Xerxes 20plus.
You have a pretty nice system. What would you hope to accomplish in an upgrade that you are not getting now from your system?

What kind of music? Budget?

The Xerxes is a terrific table and can support quite a nice arm. But I think you get better bang-for-the-buck with a cartridge upgrade. That is assuming you have a phono stage that can deliver the goods with a better cartridge.

So I think we need to know more to help you. If it were me, I already have a great phono stage, so I'd be looking at cartridges.

Hope this helps!
Your setup seems to be pretty well matched. Nothing really stands out as a weak link. If you're looking to upgrade, I think you'll get better results if you set some goals as to what you expect to get from the upgrade.

If you don't already have one, you may want to consider getting a speed control instead of an arm or cart.
Thanks Dfhaleycko & Zd542. The phono stage is the latest & improved Whest Audio whestTWO direct from James Henriot.
The arm & cart do sound good but was thinking it didn't have any balls! So I tried Don Caballero's 'For Respect' on vinyl & the original CD on my Ayon CD-3...the Ayon was far superior.

I was considering the Origin Live Illustrious as it will extract a lot more from a cartridge but that of course would mean using the AT33EV for longer.
As regards cartridges I'm looking at the Ortofon Cadenza Bronze & Blue, Lyra's Delos, Dynavector DV XX2 MkII & Transfiguration Axia S.