Offer letter for pha-f kuchlaak road project quetta

Assalam u alaikum,
Today i received the offer letter for cat-iii house at pha-f kuchlaak road quetta project. Actually it is my very first time that i have participated in property sector as i am a federal govt employee and i just dont understand that how can i collect a sum of rupees 350,000 in every three months for installments till it reaches the total amount of 45,80,000/-
My total salary is less than 50,000.
Secondly please guide me, can this offer be sold to some other person ? If yes, then what is the true value for it to be sold ?