You should be aware of the fact that safety rules for cost-shared flights are not as strict as they are for commercial air transport flights. This means that there is more risk involved in taking a cost-shared flight than buying a ticket from a commercial airline operator, where much stricter safety rules apply and where the aircraft, pilots and the operator are subject to continuous checks and strict oversight rules from the authority. As opposed to commercial airline passenger flights, the risk levels involved in General Aviation flights can be compared with risk levels found in road transportation.
I am a member of Nedre Romerike Flyklubb, which is one of the leading and most active flying clubs in Norway. The aircrafts are very well maintained and subject to continous periodic checks. Furthermore the pilot members are subject to annual proficiency checks.