It is hard to give you an accurate answer because the prices are different from different shop, different styles and shapes of the rimless titanium glasses. Usually, titanium glasses are slight more expensive than other common plastic glasses frames. The cheapest rimless titanium glasses i have saw in my life is at firmoo, a online glasses shop. I saw they offer rimless titanium glasses about 30$ per pair. You can search it at their sites. Good luck.
You can get your rimless titanium glasses from local optical stores, but they are much expensive. If you go to order them online, you will spend much less on them. However, titanium glasses are a little more expensive than regular glasses because the material is quite special. A pair of rimless titanium glasses with good quality will range from $200.00 to over $1000.00. They will cost you more if you need unique vision requirements.