As a teenager you will probably go through phases and your interest will most likely change.
The best advice I could give you which is from a lifetime of collecting is save your money and only buy quality.
If you save a couple of grand and still think the best thing you can do with a couple of grand is buy a pickelhaube your most likely on your way to becoming fully infected with the collecting sickness.
I would then recommend finding a helmet you really feel you can't live without and post some pictures here. There are many members here who would really love to help you make a good decision.
If you make a good decision and everyone here will do their best to make sure that you do and you end up buying a quality helmet at a good price you will always be able to get your investment back and maybe a little more. ( its not about the money but you certainly don't wanna be stuck with an expensive mistake you can't get rid of looking at ya everyday)
As a young collector you have a golden opportunity to make all the right moves and you have in this forum a great tool to help. One many of us wish we would have had at your age. Take advantage of it, and welcome aboard.