To focus on the original point – I think a boycott would be a justified, if ultimately doomed, venture.
There is no question that the premium one pays for a Bors is unjustified. There was a time when Brandolinos were virtually the only viable competitor, and even then they were poor quality. At that time (about ten years ago), Borsalinos were much fairer priced, as it was accepted you were paying for quality, much as you would for a Lexus. But Brandolino have improved vastly, and can now offer some quality hats, and the market has opened up significantly. Both the choice and standard has improved over recent years.
Taking this into account, Borsalino’s prices begin to look extravagant. Whereas in the past there were few viable alternatives and they truly offered a better product, in current times they are trading as much on the name as on quality. Bochurim, among others, will buy a borsalino as much for the lining as for the rest of it, and that is the problem. In such a situation, it is a perfect example of free market economics for a consumer group to take their custom elsewhere and thereby, with the frum market being one of the main consumers of black felt fedoras, the Borsalino company would have little option but to lower their prices to a more reasonable rate.
The reason why the move is ultimately doomed is because I cannot see many, myself included, being the korban, especially as if one can afford it one has little to gain from the boycott.