Stacking Sub2 & Owner Finance to get deal done

[Matthew Allen]

ARV: $255,000

Sub2: $155,000

Owner Finance: $15,000 ($5k given at actual closing)

Rehab: $15,000

I'm trying to make a deal work with the above numbers in San Antonio Texas. I am set to buy the home with hard money, then negotiated down the price for a new roof which seller didn't repair. Closing is now delayed for some old lien issues that the seller didn't know about/inform me about. She is seeing her profit dwindle and is getting anxious. I get it and want to help, but in a way that is workable for me too. My offer...I can give you about what I'd be giving the hard money lender at closing ($5k), then the rest when I sell it on the back end ($15k). For me it's a cheaper monthly payment, cheaper at closing and overall less cash in the deal since she'd basically be funding the rehab at zero percent interest.

Am I approaching this the right way, or is there a better way to look at it? I've done a sub2, but without the other complexities.