Water heater tank above ceiling leaking.

Is it repairable? Agent wants to charge $450 to replace.

How does the inside of a water heater tank look like?

My husband seal the copper pipe that he thought was leaking but the leaking still comes out from below. Where did it come from?

Can we seal it ourselves?

I'm no plumber but I have dealt with enough water heaters to know that 99% of the time, if the tank is leaking, you pretty much need to replace the whole unit.

Hot water heaters are not something to fool with. Who is the "agent ". If this is your home, $450 is very reasonable as the heater costs that much. If this is an apartment, it should be done by the owner, free of charge.