My friends do it all the time, especially with the shoes, because I do have many shoes (especially if you compare with how many they have). This is because
a) I love shoes
b) the shoes I buy tend to be good quality & not too trendy, so I can use them for years and since I have so many, I don't overuse them.
On the contrary, they buy new shoes every one or two years. The same happens with coats. I don't know, I guess it's because my family will rather buy good quality things that last than not-so-good and cheaper stuff that only lasts a couple of years. That said, I don't take it personally. Maybe it is because I know they don't say it to hurt me, I think it's more of an appreciation. Like when they see me with something new (or that they haven't seen) and are like 'hey, is that new? i really like it', so I'll take it as a compliment.
Anyways, like the girls have said, what you spend your money on is nobodyelse's bussiness (apart from husband/boyfriend/person you share your life and house with).