Being told not to buy stuff for baby

Lynzee • Mommy to Ammarie, born on March 3,2016!
My mom and MIL keep telling me not to buy stuff for my baby. I bought diapers, a crib, a travel system, and some clothes. 
They keep telling me that nobody will buy me anything if I keep buying stuff myself and that I'll get stuff at my showers. 
This really bugs the crap out of me, because it's my little girl and I want to buy stuff for her! I know I'll get stuff at baby showers, but I want to buy stuff, as well. Has anybody ever been told not to buy stuff?