People think kiteboarding is expensive...
If you are buying brand new current year gear and complaining about the costs you need to get you head straight. First of all if it's a new current model then duh it will cost more, that is the price you pay for riding a crispy kite with the newest tech. If people want cheaper they need do their research and look for deals. New old year models are often 15-40% off and used gear can be even cheaper.
The same deal goes for all goods like phones, cars, computers, etc... when the newest iphone comes out expect to pay the full sticker price to own one.
Here in the USA the used market is littered with cheap low mileage equipment. I can find 2 kites, bar, board, and harness (5years or newer) for under 1500USD pretty easy. For comparison a good road bike starts around 1500 USD.
It's also important to not forget monetary inflation when considering price. Best's 2006 Waroo started at 400usd (i am assuming it was for a 5m kite). 400 USD in 2006 is roughly equivalent to 500 USD today.
500 USD today can still can buy a new 2016-2018 small kite and so when you take inflation into account, equipment 'pricing' had little to no increase in +10years.