Your shirt should not cost the same as a glass of martini.
If you are not paying a fair price for the shirt you are wearing in dollars, someone else is paying the price for you, with something much more valuable. Perhaps even their life. The Rana factory incident in Bangladesh comes to mind.
A lot of work and natural resources (water and land) go into making of a garment. From growing and harvesting cotton to turning cotton into yarn, dyeing that yarn and using it to loom fabric; while a garment pattern is being designed, followed by cutting, sewing, washing and finishing of the garment - to name a few steps in making a simple shirt. It is a lot of work. And that work needs to be paid for. When you pay for your shirt, the money you pay flows into the hands of each person involved in the life-cycle of creating your shirt.
The problem with the fashion industry as a whole is that large fashion brands have created a business model that is driven by consumption. In other words, the focus is on selling more and more garments at any cost. That is how you can get a tee for $5 or a shirt for $30 at large department stores. The cost, however, is borne by the workers making these garments and the environment. Instead of getting paid a fair price for the amount of work they do, the workers get paid as little as $2 a day to work in large factories making cheap garments. Additionally, their local natural resources (water and land) get used to make these garments, which in the long run hurts their communities even more, when water sources dry up. And all that, just so that a tee can be sold for $5.
So, when you are in the market for a garment, ask yourself these key questions: How is this garment being made? Is the company making this garment transparent about their manufacturing practices?
You will not get it right every time, but by being vigilant about what you spend your hard earned money on, you will, in your own way, make a difference.