How are people getting multi time?

Currently I’m instructing at a mom n pop flight school with 500TT, 250 dual, 26multi. We have a multi but I don’t meet the insurance requirements to instruct in it.

I am really fortunate that a family friend has tentatively offered me a position to SIC a jet but I need 700TT & 100multi. This is an opportunity that I’ve decided I’m going to do everything I can to pursue, but I’m really struggling to find anyway to get that multi time.

If I could rent or split time in a multi I definitely would but $15-$30k is just not remotely feesible for me. If anyone has any advice or tips I am open to hearing it all and it’d be very appreciated!

CFI/CFII/MEI in the BNA area.

Edit: to instruct in the schools Aztec I need 1000TT & 25m&m per the insurance.