Decision - Finish basement or convert to duplex?

[David Hagen]

Good morning, BP!

I've got an offer in on a property that needs about 10-15k of work on the main living space, but the basement is partially finished with electrical wired and wall studs already in place for a 4-room layout.  The basement already has a full bathroom as  well.

The interesting part is that the basement's only entrance is from the garage.  This led me to the idea of expanding the property to a duplex, but I'd have to add in a kitchen, separate furnace, and separate water heater on top of making sure zoning allows for a duplex.

I could finish the basement to give the house 4 bedrooms and rent it at $1200-1300, or I could convert to a duplex and rent two units for a total cash flow of around $1600-1700, however having never done a rehab (much less an expansion to a duplex), I'm concerned about the scope of work necessary.

Has anyone seen success in this area with some advice to share? 

Thank you in advance!