Delhi property hunt: It's more confusing than I thought

Okay, I'll be honest — I thought buying property was just about the flat's price, but ab samajh nahi aa raha. I'm looking at some DDA flats in Delhi, considering both new launch and resale options. My parents keep saying resale is safer, but new launch offers seem tempting, though delivery risk ka darr hai. What all hidden costs should I factor in beyond the basic price? Matlab, stamp duty, registration ke alawa interiors aur misc expenses kitne hote hain? Aur site visit pe kya critical cheezein dekhni chahiye jo builder nahi batayega? Kaunsa option better hai for a first-time buyer?