It seems to me that PA would best be served by providing a couple of free copies, especially if they expect authors to buy their own books, and they do. I don't think many authors would want to make a large purchase without first getting a look at the finished product. But PA is not known for making logical choices and has acquired a long-time reputation for adding errors to galleys that the author has taken pains to correct. An error (among others) of adding a word in the upper-left margin on page 13 of my book galls me to this day.
They have too many authors whose sole purpose was to "hold their book in their hands" or get something published for great-granny Smith who wanted her life story published before she died. Those people never intend to mass sell the book, but if they don't get free copies, they will buy those couple for themselves and their families. The free copies ate the profit margin.