Don't talk in a position of strength when you're promoting a relatively grey area, fraudulent mechanism.

To start look on home dept and you can price out counters sinks flooring etc to get an idea of materials. 

Buy your Own MaterialsThe hot tip for the week is: Buy your materials / supplies, especially for high-priced /large / single items.

They promote using a dialer software which increases your calling success.

Also, they have limited and low quality products that you choose from for materials such as flooring  bathtubs, and lighting, etc.

Look at new construction triplex/duplex condo sales in the heights areas, subtract carrying cost over build timeline, materials, labor and construction costs, what their desired profit in heights deals would be and that would leave you with approximate acquisition cost of the lot. 

You might try wholesaling, but even that is not going to be fast - find a wholesaler, go work for him for free for a couple months, soak all the knowledge you can meanwhile and read all the material you can get from internet, BP, Amazon books on the subject.

Home prices are still high, construction labor and materials, insurance is averaging 20% a year increases, interest rates, etc. 

If they don't know how to price your unit or promote it - that might be a different problem all together.  

Take a hard look at your presentation and materials.