I think you could make the "gouging" argument when it comes to heart medicine, food, water, etc. I'm not sure what my opinion is there, but you could certainly make the argument.
But you're essentially arguing that you have a right to someone else's property at a price that you feel is reasonable. That's where I start to peel off into the libertarian lane. If someone had the luck or foresight to stock up on primers, who are you to dictate what they do with them? Or what they sell them for in a legal, consensual transaction?
High secondary market prices meet a need. It allows the product to be available for purchase by someone who really wants them. If every retailer sold primers for $30/k, they wouldn't be in stock anywhere. But luckily, there are places where resellers can list primers for market prices and now you can buy primers if you really need them.