Buying "subject to" From a Chapter 13 Bankrutpcy seller

[Robert Gomez]

I ran into a motivated seller, he is in chap 13 and wants to sell his house. The amount due to the bank is about 200k and is about 30k behind. It is not in foreclosure proceedings yet because of the bankruptcy . Am afraid if its taken subject to or a wrap that there will be more issues later on due to the chap 13?  Has anyone worked a deal similar scenario before? 

by the way the comps are at about 280k -300k and home just needs light rehab

seller wants 20k for himself