Flat out bad advice to not buy a face mask.
I strongly agree. People shouldn't be embarrassed wearing a mask, and they shouldn't simply "take their chances" with their and other peoples lives. Even if their country situation is currently not severe, preventive measures can save lives and give an example to other people.
If you are still able to buy masks -- stock on 3 - 5 of them, and dry them in a warm place for 3 full days after each use. Using a UV light source for sterilization of the masks is very effective, but you should make sure that your mask filters can be treated with UV, since some of them deteriorate on UV.
Please wear a mask, ignore any weird looks if you're wearing respirator. With mask you increase your chances of not being infected, and believe you Don't want to get infected. If you do - you simply don't have enough information about the threats that this virus presents to population of our beloved Earth.