Do not buy a share in an aircraft unless you are willing to wait a long time to sell it on again.
Also beware of the insurance issues on the machine.
What will happen if you damage or crash it? Will the insurance company pay up? Who knows? Depends on how it happened. If it was negligence, then maybe not.
And even if they did pay out it could take months.
I can't remember the exact cost, but even a replacement altimeter or other indicator can be pricey.
Hangar storage, maintenance.....the list goes on.
Buying a share is not something to get into for building, especially if you are working to a tight budget.
Have a look at the USA as an option. If you want 100 hours, you could do that in a three week vacation in Florida - and if you are not adding a rating then you can do it all on a tourist visa once you jump through the FAA hoops for validating your JAA PPL.