Yep. I was recently looking at building an art project that required a gas valve that can freely rotate while under pressure.
If you need one gas line, you can get a swivel for a normal shop hose reel for $15. If you need two gas lines on the same axis, the part is similar but way lower volume, so you have to go to a specialty supplier and the price is $350.
The business that makes hose reel swivels makes lots of high volume parts, has lots of competition, and needs to charge close to cost to sell them. The business that makes specialty gas swivels for industry that offers multiple gas lines in one swivel, lots of different options, and makes them higher quality needs to charge a lot more to keep their business operational.