Is this selfish/rude of me?

So my baby shower is next weekend & my MIL is really getting under my skin. When we told her about the baby shower she was all like “let me know if you guys need any help”, so my mom tried including her, but she wouldn’t answer my mom or tell her she’ll call back and never will. My mom got tired of trying to get a hold of her so she just continued planning with my cousin.

Then 3 weeks ago, she starts telling my husband “oh I have to call her mom to see what’s missing”. Well my mom told her like 3 things that we needed because she doesn’t trust her since she’s so unreliable. All 3 things were affordable and at a reasonable price. Since one of the items were cupcake holders. We asked if she could also place an order of cupcake with the lady she was dyinggggg for me to order my cake from. (We didn’t allow her to pick the baker because the person we use has been our baker for 10 plus years & she’s also unreliable)

She informed that they asked for $100 for 24 cupcakes. It’s steep, but it’s short notice so it’s understandable (btw this is in NYC so I think it’s a pretty good price for the short notice) however, she said she was going to look for other places. Well today my mom called our baker and asked how much for 24 cupcakes with this nice navy blue and white or silver swirl my husband wants on them. The lady said $40 dollars. I call to tell her & she’s like “yea that’s kind of expensive” which is not expensive at all. Then she tells me that she found 18 cupcakes at cosco for like 25 dollars. Wtf.

I know that $100 was a lot of money but come on $40 is not that much at all. I’m totally ready to tell her like just forget it we’ll just pay for it ourselves. My mom & dad have paid for everything. The fact that she can’t cough up $40 is beyond me especially with all the shopping she does. And I would’ve been okay with the other cupcakes if they were 24 cupcakes & if they’re able to put the swirl my husband wants.

Is it rude for me to be acting like this? & would it be even more rude if I tell her like we’ll get them ourselves?