Why all these pages of back and forth when the answer is clear: if you want tips on how to sell prints then why not simply look for a workshop including that topic. No? If it doesn't exist then try to arrange it.
The whole point of a workshop is that it has a program and reliable experts contributing to that program. If that program includes a discussion of how to move prints, well then sure you can hope to recoup losses through what you learn.
But... most workshops of which I am aware are about process, not marketing. Marketing would be really hard to cover: the marketability of people's output, their price points, their overhead expenses and their proximity to art investors are all so wildly different. There is also that central issue that no one wants to talk about: their actual profit. Everyone is happy to talk about the $500 print that sold last year, but what about the multitude of other prints that cost way more than $500 to make and sit on the shelf. How many people at a workshop would actually disclose all their gains and losses and do the math? Not many. It's an uncomfortable topic for most people. Good luck finding guidance on that!