Plot evaluation request

Assalamu alaikum,

I have a 18 marla plot in nespak phase 3 and i wanted to sell it but i'm quite skeptical because i have been receiving mixed offers from the dealers and i'm still not certain about the actual value the plot is located on main boulevard opposite to the plot is commercial area and mosque. Is it the right time to sell the plot or should i wait for the completion of kahna fly over also if i do sell it where should i invest the money for short term gains because initially intended to start the construction of my new house in dha rahbar phase 1 but i have decided to proceed with it in 2017