I was wondering if anyone knew if we have to comply with the do not call list when we call about an abandoned house, foreclosure, etc. My luck I would get hit with a huge fine…
I just looked over the rules and it seems since you aren’t selling something nor a telemarketer you are exempt. You are are trying to BUY something from them not sell them something. 
I haven’t seen any rulings from a court but I agree, if you’re calling to buy something you probably comply. There is a federal do-not-call list and many states have one as well so check both for compliance.
There are usually exemptions to compliance so if you can fit into one of the exemptions you should be okay. For example, the national DNCL allows poll-takers to call people. So, is there a way you could call a homeowner and ask a question like, “If someone offered you cash for your house as-is and could close quickly, is that something you’d be interested in?” I’ll let you decide.