In the city, the best way to buy caviar is at the counter in a higher-end supermarket, rather than in a pre-packaged tin. That way, you can actually ask for a taste before you buy and ask when they got it in. They usually have the date of delivery on the bottom of the containers, and the bowl or container should be covered in cellophane and kept on ice in the display case. You can also buy as little or as much as you need and you know what you are buying.
Red caviar is always significantly cheaper than black. That’s because there are fishing limits on the fish that produces black caviar. If black caviar looks cheap, it might be red caviar colored black, or something else. Buyer beware.
Keep it cold! Enjoy on toasted black (“borodinsky”) bread over a thin layer of butter…mmm!