It is buying a share from an existing member of a long-established group. I can afford the cost of the share and the monthlies plus the cost of the flying but don't really want to be hit with any big bills any time soon.
Aside from the points already raised, aircraft and airfield availability and how easy is it to book (and by what method)? Does it (the syndicate) require an instructor sign off/type conversion and any minimum hours requirement (I don’t know how experienced you are)?
Also are they a sociable bunch and easy to get on with? That may make life easier or more difficult, dependent on the answer...
What is availability like? Weekdays, Weekends. Are there members who pay but don't fly? Are there members who pay and fly the pants off it? Is there a CRI in the group? Are there limits to my liability if I join? Does the group ensure all members are licensed, rated, current and medically certificated? What excess is there on insurance claims and who/how is this apportioned? What geographical limits are there in the insurance T&Cs? Does any member owe significant monies to the group fund? What is my share certificate worth compared to what I paid for it? If the group wishes to expell a member (not me of course) what financial arrangements are in place?
And that's in five minutes.
Having been a member of a few groups I now own my own a/c. (Hint)
Be careful you don’t sucked into a group where everything is just too over-procedural. It’ll sap your enthusiasm and you’ll end up being a part of ‘washing parties’ and ‘admin evenings’.
They’re generally run by retired types who have little else to do, and are trying to find any excuse to not have to take Deirdre to the garden centre, or creosote the fence.
Find a group where people are of a working age where they don’t have any time to fly, they pay their bills and you’re not obliged to spend every fifth Thursday discussing whether a Goodyear dust cap is better on the wheel than one from eBay that’s 1.6 pence cheaper.
Personally, I’d only ever get involved in a group with someone I already know and trust, as I have done on one aircraft. No rules needed. It just works.