Hello Arka,
You have received much good advice here, but sometimes it is hard to decide what to do, isn’t it?
I have played wooden flutes and poly flutes, and find only a little difference in tone, and for a beginner, that little difference will not be noticed. You can always get a wooden flute later, when you know what you like in tone, and you will always have the polymer flute to play when and where you like.
I have 2 poly flutes; a Seery, and an M&E. For a beginner I would suggest the M&E, which is a little easier to play and get a good tone. I like both very much, even compared to wooden flutes.
There are two advantages about poly flutes, and that is the price, and the little care they require. You can leave them out, ready to play, and not fear that they will crack for lack of humidity. And, you can take them anywhere with you, and not worry.
So, I would recommend the M&E Rudall & Rose polymer flute:
http://irishflutes.net/mef/S_Contents.htm
as the first choice, unless you wanted to spend much less money, and then I would suggest a Doug Tipple pvc speckled bore flute in D:
http://home.earthlink.net/~life2all/dougswebspace/
Doug’s flutes are cylindrical bore, not conical, and so they will have a longer spread for the holes, like a Low D whistle, but are amazing sounding and playing flutes for VERY little money.
If you have any questions, you may email me, and I will try to help. Good luck with your choice!