The Popularity of the Kuzma 4P (11")

I was looking at my 2019 invoice of a Kuzma 4P and noticed that I had paid $6800 plus taxes (at full retail).  Today, that the price is at $10k - which is almost a 50% increase over a four-year period. Compared to my other two arms- Glanz MH124S and SME 3012 R, performance wise, the Glanz holds the top position with the 4P in close second. I do have to say that the queuing mechanism of the 4P is the best I’ve experienced – super smooth.  I have had no issues with the 4P, but I guess its popularity has increased the price point significantly. I'm also not aware of any improvements since the ruby sapphire cups which were rolled out in ~ 2018. So, is it because the arm is worth $10k or just the way things are going in today's economy or something else?