From a thrift point of view I would look at thrift shops. However, this will require cutting and sewing, how are your sewing skill. The second option I would take is an Eaton Jacket from Uniformwearhouse. This will cost about $40. Get the single button style and replace the existing button with a silver one. YES it should have a whole lot of buttons but this is on the cheap. There is a post some where on this forum where epaulettes were made out of black nylon rope. They looked good and are inexpensive.

Next month, or when the eagle fly’s high, you can add more buttons. The short jacket in and of itself will look different and sharp. Most of the people will not know what it is really suppose to look like. If you go in looking tall and proud most won’t know, those few that do know what the outfit should look like will also know the actual cost and the funds available for a college student.
Since there are few thrift store jackets in my size I am thinking of a Eaton from Uniformwearhouse as an alternative to a Argyle jacket. Manybe with replaceable buttons, black covered buttons for day wear and silver for more fancy.