I´d ask myself how much of that gear will you really use / need?
If I understand correctly, you are not planning on owning a shop. So how often do you run courses and how many participants do you have? In order to staff 2-4 divers you wont need 20+ suits, tanks etc.
What might work is: getting all the gear for a really good price, sorting out the stuff you need and trying to resell the rest. But you have to do the numbers.
When doing the numbers for the compressor you should consider the aspect "freedom". So its not only the price of running the compressor vs. cost of fills but also the question, how convenient it is to get the fills when you need them, how long it takes to get to the shop and back, opening hours etc.
that was also one of my ideas...just to resell it. Cuz to inspect all the tanks costs a crazy amount of money
Thx for ur post