15 lots. Suggestions what to do with it

I bought 16 acres    I THOUGHT it was Two 8 acre parcels.  Turns out it is an 8 acre parcel (can’t be divided) and 15 - 1/2 acre lots can build on or place mobile homes 

I sold the 8 acre lot for what I paid for the entire 16 acres 

Suggestions what to do with the remaining 15 lots?   

Partner with a builder?  

Sell them all at once?

Sell them individually?

Put a spec house on one and see what it sells for?

I have cash to use if needed 

open to any ideas.