Direct appeal to Microsoft for one-off discount

Try to find a cheaper one at Amazon or see if it is on sale in any stores on disc e.g. Argos

Another option would be a go fund me page if some of your friends and family would like to donate you could raise the funds for the discount.

Good luck with the treatment!

I think that you should approach Blizzard directly about your situation. Im not saying Microsoft may not be willing to help, but its worth a try, you never know what could happen, good luck regardless

Thanks all for your kind words and useful advise.

Unfortantely Blizzard cant help as they cant influence pricing on Xbox Marketplace.

I have reached out directly to Phil Spencer and I am scoring the internet for cheap digital download sites.

Wising you the very best, I know the situation you are facing now. I went through it in my family. Good thing is that you are fighting, and that is what make the only difference. Keep on fighting, both with condition and to be heard. Use all channels and
yo will be noticed. Use insider, reward, and administrator programs. You will help community and yourself. You will get noticed and fulfill your wishes. if nothing, sale will come again very soon...