I got my Deore M596 for about 60 quid off Rose last month. Thats for the PAIR. I had rotors already though.
I had to bleed them after swapping/trimming the hoses, which is a bit faffier in my opinion than the old Shimano brakes but not really that hard certainly compared to the likes of Avid.
Now that I have had them bled and set up to my liking I’m really rather impressed.
1 finger braking and less on/off than the SLX/XT/XTR units apparently.
They are properly powerful and for UK brakes I’m not sure you need anything more powerful. Maybe in the Alps you want the whole Icetech rotor finned pads thing.
Having said that I dragged my previous (2004 vintage ish) Saint calipers (with 160mm rotors) and XT levers round the Alps and BC for about 6 months in a year with zero issues. So maybe not.
In summary, buy either, they are both ace.
Get the deore and spend the difference on a nice new helemt or something?