Replace septic, or not?

[Marci Stein]

Seller accepted my very low offer because the prior buyer walked away when the inspector informed him the septic was corroded.

However, it is currently working fine. This is a flip. Do I spend 18 K to replace it even though it’s working fine but corroded? 
thanks !!

[Michael Brattelli]

@Marci Stein replace the whole system and provide a great product to your buyer. Raise your list price by the cost of the septic and market it accordingly. You need to disclose it either way, why pass on something you know is bad to the next person?