Manolo,
Unfortunately Rick is a little bit very right. You'd better spent your money on some good books about keris or other weapons. Even then it is hard to recognize the authenticity of a weapon. As a beginning collector you certainly will make some mistakes, like we all did.
This keris you bought is a cheap tourist keris representing a keris from madura. The scabbard and ukiran are newly made and the snakehead on the wrangka is complete fantasy. On a real authentic keris you will never see it in this way. The blade itself is made in mass production with some kind of imitation pamor and a very rudely made naga with brass inlay.
Today new kerisses are still made on the traditional way. If you can buy such a keris you may have a brandnew keris, but it is at least a good and well made keris.
My advice to you is to keep this keris a while and compare it with some real and good keris. The traditional new ones and the real old and antique ones. That's the best way to learn. To hold it in your hands and to see the differences. When you put up a small collection you have two options. Resell this keris and maybe you have to take some loss or profit when you're lucky. Or you can keep this keris in your collection as an example of the mistake we all once made. Somewhere deep hidden in the catacombs of my house, where nobody comes, you can find my mistake
