Apologize to him and tell him you will give him $5000 over the amount he owes on the house if he will sell it to you. Here's 3 reasons why he should...
The borrower/owner sells the property to a third party during the pre-foreclosure period. The sale allows the borrower/owner to pay off the loan and (#1) avoid having a foreclosure on his credit history, (#2) he gets $5000 from you and (#3) he will not have to move. (renters)
example:
He owes = 75,000
You offer = 80,000
Value of house = maybe 110000
It's easy to qualify for an investment property mortagage with those numbers.
Then you rent it to him for less.. that way you have 2 homes but the second only cost a few hundred on top of his rent... plus all of his plants are belong to you.
and you get his house for a great price I'm sure.