Bahria Enclave Islamabad 5 Marla vs 10 Marla Plots

Hi,

I have purchased two plots of 5 marla each in Bahria Enclave Islamabad as investment. I have been told that in the long run prices of 10 marla plots fetch more return than 5 marla plots. Should I request Bahria to switch my two plots of 5 marla each to one plot of 10 marla? Also if I want to invest more in Bahria Enclave, which plot size to go for?

Please give honest advice.