Why are there so many aircraft stashed away in sheds?
Because so many owners have pretty unrealistic valuations and after advertising for 2 years they quietly put it in a shed......
And years later when you talk to them they still come up with silly money prices - neglecting the rusty engine and peeling fabric.
The market price is another country in many cases.
I've been a memeber of one large and well organised group. The share value was largely not market related - shares were sold by the group - not individuals - they had to be sold back to the group. It had an engine fund and with generally 20 members it was well funded.
But we still had a number of arguments - much like these about costs and engine funds. People wanting money back when we had a large 'excess' and not wanting to pay when there were big bills.
If the group ios small these 'tensions' are likely to be bigger and potentially more destructive. If the group does not buy the share back then the arguments above about 'market value' are important.
But if you start by asking such an open question I would suggest you do a lot more research and talk to members of several groups - they will all have different views. It was my route into operating an aircraft and gave me an insight that made ownership much easier - I've never much aspired to bigger and more complex machines. But if that is what you want then sharing may be the only route - but only in a group you can get on with.
Talk to them and make sure you understand the rules. Many groups are run by poeple who consider themselves more than equal....