Look in your area for a shop that does ready-to-wear clothing alterations. Sometimes dry cleaners will offer those services. Altering a dress shirt to fit you better is a relatively inexpensive service and then you don’t have to worry about this anymore. As a 6’ tall woman, this is literally one of the reasons I learned to sew.

Cheap, well-made fabric is available at thrift stores in the form of linens. Curtains, tablecloths, and sheets are a great source of high-quality fabrics for cheap!