How do you boost ARV on tight budget?

[Torend Ebner]

I have a short sale opportunity available on a two story 3000 sqft duplex for $27k. I've got a $25k rehab budget. Zillow / Trulia estimate value at $105k.

The place needs a furnace, which will run about $3k installed. Also needs appliances in the kitchens. Will need paint in the interior.

At $52k all in, I need a minimum valuation of $70k. With this rehab budget of $25k, what are some of the best ways to boost the ARV?

Interested to hear your ideas!