I have developed a good working relationship with my supervisor and I have expressed my interest in wanting to pursue a PhD in the field that I am working in for my masters degree. I have expressed interest in a textbook from another author in a complementary field that I would want to hold in my collection as a PhD student, and if things work out, as a professor. As well, I am my supervisors first student that they have had under direct supervision after their own PhD, as are they my first research supervisor. So there is a unique 2-way relationship as well for the sake of context.
My supervisor has told me that she would be willing to purchase this book for me and I think that my supervisor would be doing this because they actually want me to have it for my future and in part as a gift to me. Personally speaking, I do not see any ethical concerns with this, but I suspect that I might not have a complete perspective on this type of exchange. Do you think that there are any ethical concerns that I should be cautious about?