The 2nd Amendment only guarantees you the right to own and use a gun. It says nothing about the particulars of doing so.
A quick note on the law itself: The MN concealed carry law was very carefully crafted by the people who fought for it, with very careful attention to even minimal bits of language (such as “when retreat is not possible” vs what ours says “when retreat is neither possible nor practical”), and, considering the bajillions of man hours invested, we got a damn fine law.
That’s got nothing to do with the cost.
The supreme court just upheld the right of everyone in the country to own a gun by overturning the restrictions in DC and Chicago. However, being able to own and shoot a gun is a substantially different matter than being allowed to carry one on your person, loaded and close-at-hand, in public. THAT is not a right, that is a privilege.
I don’t think the cost is prohibitive and I believe that, considering the gravity of the choice to carry, it’s enough to make you take the permit seriously. People by nature respect a thing only as much as it cost them to obtain, and I think the cost of the permit reflects that quite well.