My husband and I are big proponents of the International Gem and Jewelry show. He got my engagement ring there, and we got both of our wedding bands there. The great thing about it is you have a huge selection from the hundreds of jewelers that are there, and you can pay even less that wholesale prices. For example, my engagement ring appraised for almost 4 times what my husband paid for it there. You will certainly be able to find affordable titanium or silver rings there. You can even get high quality white gold rings for extremely cheap.
The show is travelling, and it comes to this area about 4 times a year. It will be at the Dulles Expo Center from May 18-20. Even though it is a hike outside the city, it is totally worth it. You can find out where else the show will be one their website: http://intergem.com/index.php