What to respond to seller?

[Dwayne Jelks Jr.]

I was doing driving for dollars and found a burned property in my area. I called the seller immediately, he didn’t respond, but instead sent me a text. I offered to buy his house as is for cash. He responds what’s your offer? I respond I can’t give you an offer over the phone because I have to do homework on the property. Then he responds that someone offered him 150k already for the property. I texted him back and asked if I could give him a call and ask a couple questions about the property. He hasn’t responded since. My question is what should be my next move going forward? I know there’s a bid on the house for 150k and the seller don’t want to talk on the phone.