My advice is don't buy the brooks...even if you can resell it for full value you need money now for things you simply don't have.
You have a saddle. You haven't given it near enough time for your bit to break in. It took me two months for me to adapt to the saddle that came on my bike.
The brooks or any other saddle is not a magic bullet and is going to instantly make it stop hurting.
On top of that, you are young, and if you keep at this, your going to thin down relatively quickly and your going to want a different saddle then anyway.