OK so it's perfectly clear that unless you have the CPL/ATPL you can't get paid to instruct - but what counts as 'getting paid' or 'valuable consideration' as someone recently put it? For instance what about logging the hours, is that not considered 'valuable consideration' and thus out of bounds for a PPL FI, and how about if as a PPL FI you own the aircraft - do you have to 'cost share', or can the student be made to pay 'cost price' (obviously not to make a profit otherwise a CPL would be needed).