NO NO NO!! You are looking at it all wrong!! Let me help you with this.
Firstly, What kind of brand are you into. And what kind of car type are you into.
Secondly, Search on websites like idcow.com diecastcollectables.com and diecastfast.com and see if there are cars that call out to you. If you get a chance to buy from abroad, always buy things which are unique and which cant be found in India easily. The cars you have mentioned above are generally available here.
I would suggest things like: The Minichamps SL65 Black and the Mondo Motors Zonda primarily.
Another thing you can do is go streamlined. (This is what I would do) Go after one particular brand only. This is what I did when I started collecting. First I started with Ferraris. Then Muscle cars. Then Tuner Japanese cars. Then I progressed to a more serious phase where I decided to collect Mercedes and the occasional BMW. In the Midst of all these, I bought other cars that I liked, but was always on the lookout for a Good Merc. I still am. That is how you make a collection. Of course, You have to add a dash of Exotica in the mix. Another thing you should remember is, Be Different from the crowd, Never buy what everyone buys. That is why I dont have a Reventon yet.