When I was driving over to the school I fly for, it was a good day if the small amount of pay cover the fuel expense to get there and back. Now I have my own Aircraft to use to transit, the time and fuel costs aren't as much and if the weather is off then there is no flying anyway.
I knew from the start, earning an instructor rating and instructing on saturdays would cost me way more than I would ever earn.
My motivation was and still is to keep working on my own skill and ability and that sure is the case while working though the rating course, plus I believed the challenge of teaching student pilots , both in the aircraft and on the white board, would be extremely satisfying. It is, and if I can help someone learn the skill and procedures of flying an aircraft safely whilst continuing to build my own skill and discipline, then that is great, and so far I have no regrets.
Best thing is, each week I still do the countdown to saturday , watching the wx forecast with anticipation...........can't wait.
cheers
JimG