Pre Op shake question

Hello to you all..

I was wondering where I can get low cost protein powder or shakes.

We are on a very tight budget.

Any help will be thankful for

walmart. pre-op= any low carb whey

post op- depends on surgery - look for whey isolate.  

Costco - they have good proteins - and often they have coupons. They have powder and premade.

don't forget vitamins and minerals. I get mine cheaply in CVS when they have B1G1 sales.  I typically get their brands - and multi- CVS Spectravite works great for me.