Felix
If you're still with us, apologies for the way everything's gone away from your original question.
I've shared boats and aircraft. How well it works will be dependent on how well you get on with your partners. Most of us have neither the time, the money, or the obsessiveness to want to spend all of our leisure time playing with the toy. However there are some who want to do lots of hours and want the machine to be available whenever they want.
If you buy it yourself you end up with all of the cost and all of the risk, and have it available to you whenever you want. You'll also know that it hasn't been mistreated.
If you share it you share the costs and risks but you give up some autonomy and availability. The dictum of "buyer beware" applies equally to buying an aircraft outright as much as to buying into a group, but you need to be more careful with a group because, while things may unexpectedly go wrong with the aircraft, they can equally go wrong with the personal relationships within the group.
Don't pay more for the share than it's worth. Make sure you understand the value of what you're getting. Don't value the aircraft by asking prices, think of what similar aircraft sell for, rather than the price they are advertised at. Make sure you understand what expenditure is likely, will the engine need an overhaul, will it need a repaint or re-cover, will it need a prop overhaul? What will the costs be? Is the pattern of expenditure likely to be similar to what it has been (in which case the group accounts are likely to be a good guide) or is there something expensive looming like an engine overhaul? Are changes like the increasing cost of Avgas going to increase or decrease the attractiveness of the aircraft to future purchasers?
All of these are things you should also be condidering of you're thinking of buying outright.
One could go on ad infinitum, at the end of the day it's what you feel comfortable with.
Some people want to have their cake and eat it.
Nothing wrong with that, it's having someone else's cake and eating it that gets you into trouble.
