Anybody know what this might be or
how mandatory it is to be fixed and how much it would be to get repaired
Can’t really tell. It’s in silhouette. Maybe part of the muffler hanger.
Judging from the rust on the other parts the prognosis might be terminal.
Best to visit a mechanic.
It looks like a bracket for parking brake cables to me. I would guess new cables needed. You would really need an estimate to see what all needs replacing. Hopefully $100 would cover it. My guess.
I zoomed in . . . definitely part of the exhaust hanger, as @circuitsmith already stated
Go to a reputable exhaust shop . . . not Midas, Meineke, in my opinion . . . and have them put the car up in the air for an evaluation of the car’s exhaust system. It obviously needs some attention
The rust doesn’t look too bad to me, I can still see paint on the frame.