I told my mom that I can't wear just any type of Pointe shoes and they have to be made for my foot type. But she thinks all Pointe shoes are the same so she is trying to get me Pointe shoes that are on sale in our dance shop. Can you tell her what can happen if I have the wrong type of shoe? -Peddy- ...I was so glad to receive this e-mail from a 13 years-old “student” of our educational newsletter series called “Pointe shoe academy”: this means that we are doing good deed, helping young dancers understand the importance of pointe shoe fitting before they have to deal with the consequences. So I put a lot of thought into the reply, plus, I asked my Facebook friends – professional and amateur dancers, teachers and parents… So, here is what happens when you use a badly fitted pointe shoes:

 

1. Pain.

Please do not beleive this outdated opinion that every ballerina is in constant pain "by default". A properly fitted shoe is supposed to protect and and to support your feet so they are NOT in pain.

Pheobe Despo, dancer: 

personally from bad fitting shoes I have gotten: nerve damage in my foot (which took a year to heal)..strained the top of my foot multiple times...lots of bad blisters....and also it prevented me from trying my hardest in class and going for stuff because I was worried of rolling my ankle (preventing me from improving)...
I've also seen dancers around me suffer similar and worse things....the wrong Pointe shoe fit has the potential to ruin a career...

2. All kinds of injuries

When en pointe, your feel are working in a totally unusual mode and in some very difficult conditions. You may develop all kinds of irreversible anatomical issues, especially if your feet are still growing.

Irene Arnold, Dance Teacher:

I always ask people to think about what they are trying to do. Just imagine, all those tiny bones in your feet, bound by satin, paste and cardboard- supporting your full body weight on a platform that's only an inch or two wide. You can instantly picture the bones stacked and realize the support and fit needed must be as close to perfect as possible. No mother I know would like to picture her daughters precious feet collapsing, rubbing, and potentially being caused irreversible harm from an ill-fitting shoe just to save a couple bucks at the dance shop.

3. Constant distraction from your goals

You will center your attention on your pointe shoes (how to reduce pain, how to get en full pointe etc etc) instead of upgrading your skills and dance talent.

 Grace Campbell: Kineticdanceproject.com

In our studio, we are education parents as well. About pointe shoes, in particular, we are sending them this newsletter:

We have received several inquiries from both parents and students with some misinformation regarding the selection and function of pointe shoes. While a discussion has been had with the students in class we thought we would take this opportunity to also inform the parents as to studio policy and offer professional recommendations. Due to professional liability restrictions, potential long term nerve damage, structural damage, and anatomical disfigurement, pointe shoes that are not professionally fitted and instructor approved will not be allowed to be worn inside class. As pointe shoes are an expensive customized safety aide, we strongly recommend that all parents and students purchase only after a consultation to avoid loss of funds. When purchasing shoes things that are consider and semi customized will include the strength of the shank, shape of the box, height of the vamp ect. This is all in consideration of the foot shape and is intended to support the dancer in both stability and lift. Pointe shoes are very much function and asthetic. As a professional who must protect the dancer and the business, there is no room for compromise on this very important matter. Additionally, ill fitting shoes cause pain, causing the dancers to compensate by using short cuts and weight shifts that compromise thier ankle stability, body and ankle alignment, thus causing them to use the incorrect muscles. As all of these outcomes are both undesirable and dangerous we hope you can support your dancer and or position. Please help us insist to them that there are no shortcuts worth thier safety nor is it worth undermining thier years of hard work by tanking their technical training. Thank you for your guidance and cooperation in this matter.

4. When you pay more, you actually save! 

Pointe shoes that don't fit, break way sooner than the perfect ones. A wrong shoe will try to adjust to the foot, will deform and break down. Besides... later, when you know what's you perfect model and size, you will find so many ways to get the same shoes cheaper... 

Rahela T, Dance mum.

Even if they are on sale (and I do understand the financial side being a "dance mom" myself), the fitter at the dance shop should be HONEST not to offer wrong pointe shoes, no matter how many remain unsold. 
So the first advice would be to CHANGE THE DANCE SHOP. And also to look for offers ONLINE for the PROPERLY FITTED pointe shoes.
So once you get properly fitted you can always keep track if YOUR shoes are on offer somewhere.  Besides,  if/when a dancer damages her feet, physiotherapy costs a lot more than dance equipment...