Seller Finance Flip?

[Bo Bowell]

Not sure if the terminology is correct here. I'm a wholesaler looking to do my first and we have a lead on a property that I've been working with the sellers for over 10 months now. They haven't been paying their mortgage since before I started talking to them. I have offered to take over the payments, pay the late payments and give them some money to move on with. Numbers are below. 

I know it's not a great deal but I really like these people and would like to get my experience boosted for better HML rates in the future.

Owes: 170

Behind: 15

Needs: 8

Rehab: 60

Duration: 3 months, input 9 to be safe

ARV: 315

Am I missing anything? To me, the PP is still 178, I'm just paying 15 upfront. 

The fact that i am removing the purchase and the associated HML costs is what I am having a hard time wrapping my head around.

Any help would be much appreciated.