I didn't buy an engagement ring. I bought a two-piece wedding ring. White/Yellow gold with diamonds.
For an anniversary I bought a really nice necklace and bracelet that was very expensive, (at that time it was just shy of about 3 months income), and ya know what happened? She lost the bracelet less than six months after she got it, (still has the necklace).
For a Christmas present, one of the things I bought her was a higher quality european watch, two-tone, self winding, locking bracelet, (you know the kind). Well all I've heard about is nothing but bitching because it is self-winding and if she doesn't wear it for a couple of days, it stops running. Then she can't get the crown to unscrew to reset the day/time. So, I bought a watch winder, gave it to her, plugged it in and showed her how to use it. The damn thing collects dust, and is never plugged in.
I don't believe in expensive jewelry. I will buy myself another pistol before I spend any large sum of money on jewlery, and whatever is left over she can spend at walmart for socks and sweatpants.