I feel that if it's financially possible, it is important to get a diagnosis. I have found that having a diagnosis makes my friends and family take my diet much more seriously than they would otherwise, not to mention ME taking it seriously. I also found that after getting a diagnosis, I followed up on a few issues that many celiacs commonly suffer from, and found that I have severe osteoporosis for my age. Now I'm focused on treating it. I never would have known had I not gotten a diagnosis.
That being said, I hear you on the no insurance thing. I'm lucky enough to live in Asia where I can afford medical care, but if I were in the U.S., there's no way I would be able to get the kind of care that I am getting here. If you really can't get tested, I think you have to make a choice to commit, COMPLETELY, to the gluten free diet. If you go halfway, you could open yourself up to a lot of other problems and suffering in the future. But it sounds like you really have to deal with the repercussions of eating gluten, which show up in the form of DH for you, so you're probably not as tempted to cheat as some people might be!