Blue ones(It's only worth making if you use azoth to make them blue) on my world go from anywhere between 600-1500 depending upon the city. Wherever they are made(the settlement with the tier 4 station) they will be the cheapest, as people just make them and list them there. If you run around to the other 3 starting zones and brightwood, you will fetch a much larger price for them as they will be the only/close to the only ones up there.