Brochure prices are a total lie, agree?

Okay I'll be honest — I completely underestimated how confusing this process is. My Home Constructions ya Salarpuria Sattva mein 3BHK dekh raha hun Gachibowli side. Brochure price toh kuch aur hota hai. All-in cost mein kya kya chupa hota hai, yaani PLC, floor rise ke alawa? Sunna hai possession ke time bohot hidden charges aate hain. Kaise pata karein?