There was a post like this in the CFI corner not long ago, that I replied to, but here's the gist of my post. The school I'm currently instructing at, had an insurance requirement, that all instructors have 10 hrs in type, for one of our aircraft (Alarus CH2T...........dunno why they wanted the 10 hrs in type, but they did.............whatever.). I was allowed to do "scenic" flights in the airplane, and anything that wasn't considered strictly instruction, to work towards those 10 hrs. However, that may have taken a month or 2, and during that time I was missing potential students. So I ended up paying for about 7 hrs of that time, to meet insurance requirements. Now, they didn't make any profit, they gave me the plane at cost. If they'd actually charged me the full rental rate, I may have not been so ok with it, but I understood it for what it was, just (another) stupid insurance requirement. That requirement, as an aside, has now gone the way of the dinosaurs with an insurance company change, always did think it was stupid.
So, to answer your question, yes, I did pay to get "checked out" in our planes for instruction. In fact, I think I even had to pay to fly each of our aircraft to be checked out (Alarus, 172, and an Arrow), but again, only at cost.
Also keep in mind, at least on the positive side............any $$ you spend on an aircraft checkout to instruct, is tax deductible. Saved me from paying any taxes this year!