Paying for a diaper cake?

Elaina

So I had just posted on my towns Facebook page asking for recommended pediatricians in the area. I’m a FTM expecting in June. Some woman saw my post and messaged me saying she saw i was expecting and that she makes diaper cakes and is the cheapest around if I was planning on having a shower. I know I sound naive but I’ve never had a baby or a shower... I always thought ppl made those diaper things and brought them as like a gift? Is there any reason I should buy a diaper cake other than it just being a cute decoration for the shower?