I 10/4 islamabad plots.

Aoa.
We have a plot in i-10/4.
We have copy of its documents while originals are misplaced.
I have a copy of payment that i have made as its development charges.
Its on my fathers name and we have bought it in 2004. Was bought from allah dada khan.
Its actual location is behind those brick klins.
Now we are basically concerned about the price of plots in that area (more specifically the one which is just after those last house behnid the klin.
And the procedure of selling it and some trustworthy person whi can assist me in this regard.

Jazakallah and thankyou in advance.