transition glasses, also called photochromic glasses, are made of transition lenses (photochromic lenses). And the cost of a pair of transition glasses consists of the cost of glasses frames and transition lenses. So, it is hard to tell how much does a pair of transition glasses costs. But i saw glasses frames and transition lenses are in low prices at Firmoo. Their transition lenses are only sell about 34 $. So, you are likely to get a pair of transition eyeglasses less than 50$ at firmoo.com.
Transition glasses are also called photochromic glasses, which are specially made for people who often go between indoors and outdoors. Transition glasses can turn dark when you go outdoors due to the exposure to UV rays directly and turn clear indoors. So they are very convenient for people who often go between outdoors and inddors. Transition glasses usually cost $30-$70 at online optical store, which are much cheaper than the local stores.