Good timing - I was just about to search the archives on the subject myself.
For me, I would be using all my savings - presumably it varies from group to group whether they would buy back the share at any time, or you have to sell it yourself?
The other thing I would be concerned about is suddenly finding the a/c needing a new engine, and having to cough up for it. Again, it seems to vary whether the hourly cost factors in money for overhauls etc.
What are the traps to watch out for with a/c type and revalidation by experience?
Is it a good idea to go for a group where a share-owner is an instructor?