I know some people will have strong views on this but I get a lot of medical supplies from eBay. But I always check the name of the seller and the feedback and also the sellers write up on the product before I click buy. If it's the slightest bit dodge I don't buy. I know I take a risk on eBay but generally I can get what I want in bulk for cheaper than most high street or website shops.
Anything I can't get on there I go to a reputable pharmacy.
“Tough times don't last, tough people do, remember?”