The TAE is not a requirement for the Instructor rating and is not required if you are instructing in a Part 142 school. There is a wide variety of TAE courses, ranging from outright scams, 2 weeks and $800 to 6 months and 2k (both of those are a part time load). So too is there a wide variety of Instructor Ratings, from 32 hours flying to 45 hours. Gone are the days of 30 dual/20 mutual. I doubt that candidates even check how many flying hours are included when they're googling around. Buyer beware and all.
It is rare that a candidate self funds these days, they want it all and they want it now. CPL/ME-IR/Instructor Rating, all done in about 230 hours. And you'd all be pleased to know that quite a number of these courses are pushed and promoted by government institutions, TAFE's and Uni's. And they do-not-care who signs up. The could not care less what sort of financial difficulty the student will end up in. That's probably the job of a good parent, the financial education side of things.
If a candidate is smart and secures a job at the 'right' organisation they'll actually be using that ME-IR relatively quickly, in and out in about 2 years and ready to move onto/into an airline gig.