You give them a price that makes them go away or makes a helluva deal for you.
This is a thing that happens in almost every craft. I've done it myself.
One thing I have to mention though, I'm having something 3d printed (a half scale helmet) and it's costing me more than the Kylo helmet. If these are genuinely 3d printed pieces then actually they're a steal. Try getting a quote for a full scale helmet from shapeways in whatever their ultra high detail material is now and see for yourself.
I had a full scale batman Arkham Asylum cowl printed for a 24" head via shapeways and it was under $400. Or course, the purpose was for casting and making urethane castings so the helmet was all of 1/8" thick, if that. Not sure how something 1/2 scale (which is 1/4 the volume) should come out over 2k - unless it's solid or a high end material.
That powder method sounds a bit newer than the older ones i saw. And by older, i mean circa 2001. The was a plate that set atop a bed of powder. Ultra fine powder. Finer than flour. When you started it up it set a certain level of power ontop of the plate and went over it with an inkjet head. the 'ink' mixed with the power and turned solid. The plate then descended like a micron or whatever at a time until it was done. Those were fragile and not expected to live long lives. I can see that method being used for props these days in that they're problably pretty cheap and you don't need them very long. If you can just 'print another', who cares if if it's the same one used in E7, or 10 or 24? It'll look pretty much dead on. So, for production sake, they only have to last a few months, if that.
Now, as for selling to the public. If they're as fragile as they're made out to be, it's pretty stupid. Shoulda sprung for stronger prints or something that'll last.