First, customs aren't banned. That was something that was done to appease Sideshow, but they went ahead and pulled funding anyways.
Second, the issue is that in order to sell items based on someone else's likeness, you need to have their permission, Buffy didn't do that. Ergo, laws were broken.
You look at it from Buffy's perspective of all the work put into the sculpt. But what about all the work that Ford, Scott, and the film crew put into Blade Runner? Don't they deserve compensation for their work? Buffy is profiting from their work without compensating them.
I think that argument is a little unrealistic if you're then going forward and supporting an unlicensed figure. Within the confines of the unlicensed world there are good actors and bad actors, it's pretty simple. Nobody can acquire the Blade Runner rights. So starting from that point you can behave badly in creating a figure (copying someone's work) or create something from the ground up.