Issues with "sign the deed over to you"....

I’m in Northeastern Oklahoma. Was just offered several lots (most have mobile homes on them, collecting monthly rent). The person I’m dealing with is a relative of the owner of the lots. Until recently. That relative just “signed over the deed” to all of the properties to my contact. She was owed money and by signing over the deed the debt is settled.
They now want to sell me the lots. They have offered to “sign the deed over to me just like her relative signed over the deed to her” when we settle the payment terms. They are young and don’t want to deal with the properties and want to get money in their hands as quickly as possible. I had them sign a purchase option document and gave them $1000 to give us a week to sort things out.
Can this type of transaction possibly be as simple as that? I know that when the deed was signed over to my contact that there were taxes owed and I expect to have to settle that. And to search for liens.
But what else (besides contacting a good real estate attorney) should I be concerned about?
I am quite the newcomer to this type of business and would certainly appreciate any and all suggestions.
thanks very much!