Greater Noida West mein builder charges aur rental income ka sach?

I'm based in Dubai and my agent is really pushing me to finalise a flat in Greater Noida West. Booked a 3BHK with Gaursons, construction-linked plan hai. Ab builder bol raha hai ki material cost badh gayi hai, so extra payment for PLC. Mera budget hil gaya hai. Also, they promised a 3% rental yield in Noida Extension. Kya ye sach mein possible hai? I can't do site visits ya manage tenants myself. Anyone else faced these hidden charges from builders in GN? Aur rental income ka kya scene hai wahaan? Need honest advice.