Found A Motivated Seller...What Are The 1st Questions To Ask?

I have just found a house very close to where I live. It has been on the market for about 9 months now. First it was FSBO, then realtor, now again FSBO. The people just moved out about a month ago, so it is empty. I noticed that last week they resodded the back yard. It is 2187 sq. ft. and on the market for $152,900. I want to call the seller, but need some advice on the first questions to ask? What should I be looking for? Can I ask them how much equity is in it or do I need to call the bank? Help! Thanks!