Also, perhaps I wasn't explicit enough in my original post, but the plan is to get engaged during law school so that I can marry after I graduate, not while still in school. My girlfriend is a sentimental person and she would want to keep whatever I gave her during a proposal. She is traditional when it comes to something like this and a ring is what she would want versus some other type of token; she would want to be able to signify a traditional engagement in some way. Therefore, I am thinking of going in possibly one of two routes: to either go all out and go for the perfect ring or to get the perfect band and setting with the plan of replacing whatever I put in there with something better down the road. I think my father has already figured this out as on the phone the other day he made a comment, "you would say something to me before going ring shopping, right?" That complicates the situation because I have a feeling that both my family and hers would expect a nice ring. And I believe that the ring needs to come from me, not from someone else offering to provide funds for it.
I appreciate everyones' feedback. Thanks!