Well, if you buy the shirts from the local pilot shop (which is a five minute walk from the school), you can expect to pay between twenty and thirty dollars per shirt. The bars are about eighteen dollars per pair.
I purchased my shirts online from
pilotshop.com. They are inexpensive (I paid fifteen dollars per shirt), and they have a much more expansive selection than the aforementioned pilot shop. If you are a non-regular size, you will have to order online. For me, at 6'2" with a 28" waist, I had to get tapered shirts that even only a handful of online pilot shops carry with the features I wanted.
When purchasing your shirts, three would be a good number, utilize some foresight: fine cotton shirts wrinkle
very easily and are typically more expensive. Short-sleeve shirts are the "norm" for Commercial Pilot Apparel; speaking of which, get shirts that have eyelets for wings. Although the Aviator Students do not wear wings, you will wear wings once you get to an airline (or become an instructor.) Certain airlines, like American Airlines, have wings that cannot be stuck into the shirt like pins, they
require eyelets. For those airlines whose wings are pins, the eyelets will simply make it easy to align your wings properly. Also consider the pockets, I have found that the fake pockets (completely open at the top, like front pockets on your slacks) droop and look very unprofessional. For my shirts, I have pleated pockets, with button flaps, and pen pockets in each. They stay nice and crisp, and serve their purpose well.
It has been my experience the Van Heusen shirts, if properly taken care of, will last for years.