Any idea on the price and weight difference between them?

http://singletrackworld.com/2017/06/sram-trickles-1×12-technology-to-gx-eagle/
425 for the 12sp group at RRP – 11sp check your online retailer etc.
also SRAM website publishes all their “claimed” weights

425 is rrp though, be surprised if it was sold for that…

£425 at Tredz for 12 speed. £378 from Ubyk for 11 speed.

how many cassettes do you go through? £180 rrp for a new one.

Closing in on 4000km in all conditions on the 11sp GX here 🙂 Outlasting everything previous to it.

Closing in on 4000km in all conditions on the 11sp GX here Outlasting everything previous to it.

No idea how many miles mine has done, but it is lasting really well. Over a year old, ridden in all conditions etc. Not changed the chain – I’m just going to leave it until its all shagged and change it then.

£380 here: http://shop.18bikes.co.uk/m9b40s634p2791/SRAM-GX-Eagle-Drivetrain-package-2018

3000 + miles on the cassette.

I’m holding out for SRAM vulture 1×13

Wouldn’t put too much stock on the RRP of the cassette either. Standard 11sp GX RRP is something like £120 but regular price is more like £75.