Help! How do I proceed with this deal?

[Account Closed]

Hello All! It nice to be here. I'm new to the site and new to Real Estate investing. I found 3 little one bedroom houses.  Ok, I admit, emotion got the best of me. But as I looked closely (well, remotely) at the units via google and I fell even more in love with them.  I contacted the sales agent and offered $18k for "all of them".  I made an offer and asked if the seller would be willing to accept monthly payments until they are paid off. In addition, they would continue to collect the rent until I paid them off to cover interest.  

The seller called 2 weeks later and said that she presented the offer to the sellers for the four houses and they are going to run the numbers and get back to me. 

I haven't done any inspection and really have now idea what I should be doing to prepare for a counter offer if there is one. They are very old homes. But I assume they are not in too bad a condition since they all have current long time tenants.  I figured, I'd let them come back with a counter offer then fly down and do an inspection.

I really want to get these homes and rehab them. I'm going to look into getting an equity loan. But are there any suggestions on how I should proceed with this situation? Is this a good deal?

 To a novice, it sounds like a good deal. But i'm sure there are things that I haven't thought of that I need to take into account.  My goal is to buy and hold these properties. They've been on the market for  about a year and a half.

Please help.