I can understand where you guys are coming from. I was with my guy forever, we bought a house, he just finished school and I am still in school. I basically told him that I don't care if I get a cracker jack ring, but I would like something! I think that he had pressure to live up to the ring his sister recently recieved, as well as the big bling that rocks his female family members fingers. I felt that if he was waiting for the money to afford that, (he doesn't want anymore things on credit either) that we would be waiting forver. I think he got the hint and it became really important to him after he finished school to make it official in his eyes. He still calls my ring a starter ring, but I am totally happy with the half carat solitare.
People outside of the relationship can be really stinky. They don't quite get it. And parents I think are just old fashion and need to see that as a commitment that things are serious.
I would just mention it to him if its bugging you a little bit. You can totally do a CZ or even a gemstone e-ring. I have seen quite a few of those lately. Sapphirres or rubys or even yours or his birthstone, or the stone from the month that your getting married in. A close friend of mine has a ring that is mainly a blue sapphirre that has some diamond accents. She just isn't a big diamond person. Its something to consider.
Fh and I were talking last week. He said he wanted to propose again and that after he did we would get married a year from then. So i'm excited, I now understand why I hadn't received my e-ring yet, even though we have been engaged for more than two years. He should be proposing again pretty soon.