If you insist on flying carriers with no interline agreement, at least hedge the fare savings with a decent travel insurance policy which kicks in at 3-4 hours of delay and pays for a new ticket within some parameters.

If the cost of the policy isn't worth the fare savings, have to ask whether it's really a savings in the first place. Especially true if you are on a tight budget with a family. A couple of hotel rooms + food for a one-day delay can push some people over the edge.