Noida upgrade: negotiating VKG Group in Sector 25 YEIDA

Sector 25 YEIDA keeps coming up every time I shortlist something. I'm currently in a 2BHK, looking to upgrade to a 3BHK or villa for investment. VKG Group ke projects dekhe hain. Pre-launch prices pe kitna negotiation possible hai, ya spot discount better hota hai? All-in cost mein kya hidden charges expect karu? Builder ka delivery track record kaisa hai?