It's also influenced by the market being a really small one. Less than 200 Gulfstream V aircraft have been produced so far. Compare that with over 10,000 each for the B737 and A320. Add on the typical crew-to-aircraft ratio being 2 or 3 crews per aircraft for a business jet - in contrast with 4-6 crews per aircraft for a midsized airliner. So, there are just a handful of Gulfstream V crews globally. Maybe 500 crews, making 1000 pilots total in the world. Maybe even less. Controlling such a tiny market and establishing monopoly in it is far, far easier than even attempting to control the huge market for the mainline aircraft. And, in addition, just about any price can be passed with the excuse of "It's a premium product, you know".