Where are you seeing a 2nd hand Mavic Mini (MM) with 1 year warranty for £260? Do not give the exact address otherwise you might have competition but if I were you I would be inclined to verify the existance of the warranty.
I am suspect that my 'take' will be contrary to the popular one but I find the MM adequate to good if flown with its limitations in mind i.e. when I suspect the wind will be consistently strong I don't fly it. However I do have the advantage of a better drone for windy conditions so I am not limited to only the MM.
So far, when my MM has been caught in a squall, I have been able to either descend into slower wind or ride out the 'blow away' and no, I have never been in a situation where I was beginning to worry about getting it back.
I am NOT disputing that the added speed and wind resistance of the 2 is an advantage and unexpected winds can occur but I would suggest that planned flights where the advantage would be considered necessary are a bad idea. For either drone I would suggest you read up on how to deal with blow aways and the effect of gimbal tilt on the maximum available flight speed when in wind less than "strong".
With regards to Occusync, I do not dispute that it is an advantage both in terms of maximum range and surety of the connection in areas of interference and I do not fly over built up areas FULL STOP. But with my MM I can normally get to, and beyond, the limit of my VLOS, 400m to 600m depending on the background etc.. No I do not make a habit of flying beyond my VLOS and as far as I know VLOS is still the legal requirement in the UK.
So far the only times I have had the connection weaken when closer than my VLOS was in light mist/drizzle and possibly (vague memory) a significant number of trees 'in the way' though I still had VLOS.
I have had my MM out to 2km at a height of 20m or so over open sea and it lost connection slightly over 2km but regained it as it climbed during RTH.
Other considerations, I am pretty certain that if you go for the
Mini 2 with only one battery you will soon be looking for additional batteries and a multi battery charger and probably a charger.
The 2 has another advantage that I haven't seen mentioned so far, the much greater battery capacity in the controller but that only becomes significant if you have multiple batteries and use an Android screen device. Conversely I think the increased size of the controller is a slight disadvantage.
All the above said if I were a newbie I would probably opt for the
mini 2 but the flymore kit rather than just the drone and 1 battery. At a rough calculation 2 additional batteries, the charging hub, a charger and the bag are £170ish bought separately vs a £120ish increase (going by the current normal UK retail prices) if you bought a flymore.
That said, your "£360 new" is a very good price but is it from a UK retailer? Be wary of import duties if 'foreign'.