Instructing has always been poorly paid and probably will always be. After you take into account crap weather days and brief/debrief time you will earn a decent amount more working in Lidl.
Instructing has always been about building hours to get the big break. If you are older in years you have to seriously take this into account as the odds are stacked against you.
Did I regret doing it 18 years ago - definitely no.
Would I go through it at my age now (almost mid 40) - definitely no.