Scoobster
May I share my experience as someone who has been trustee of 4 groups over 25 years flying C of A aircraft (B121, C182).
To achieve enough utilisation to justify ownership (with UK weather) all partners need to be IRr rated and the aircraft suitably equiped.
Having a CS prop will add significantly to the maintenance cost (6 year o/h).
I think your maintenance estimate is far too low - expect £4-6k per annum and be prepared for the unexpected - I've had top-o/h 35hours after excellent compression test (£10k), new prop due to corrosion at 3rd o/h (£10k), avionics repair (£3k) etc etc
I've also had to factor respray (£9k), avionics upgrades (£8k & £6k), interior refurb (£4k) etc
There is nothing to beat owning a share in your own aircraft . However flying a C of A aircraft in EASAland is very expensive and I have witnessed a lot of groups at my airfield fail due to an inability to meet the ongoing costs.
Please don't be put off by my rambling, just enter ownership with a realistic awareness of the potential costs.