it may help us to know what you spent ?
i spent 2 years doing an "internship" which basically means i was free labor. i would have preferred to pay the cost and begin teaching sooner. but i was told that was not an option. so my situation may not be a good comparison.
i started as an ow diver with padi advanced and nitrox. there were a number of prerequisite courses i had to take. science of diving, search and recovery, equipment repair, and probably a couple more
then i had to fly to grand cayman to do my final examination. this was an unexpected cost as we were originally told we could do our IE at home.
all in all after spending 2 years and logging a few hundred hours interning, i probably paid out about 3000 to 4000 dollars just to get to reach ow instructor..
i have calculated to achieve my current instructor status it has cost me about 10000 to 12000 with courses, equipment purchases, travel costs etc. it has taken me 3 years to earn back that amount.