I completely agree!
I had to find one-pump rubber hoses connecting the LE with struts for a SS Fuel 2004 and it was impossible! Had to search all stores in my city and bought something useful in a specialized shop for water/gas/oil hoses...I only paid 3 Euros for 1m, but it was not the exact material....
The Naish Shift bar spare parts are so damn expensive! I cut 3 lines (1 front line, 1 rear line and 5.th line, after a touch of 2 sek. with a BEST Waroo kite) on my Shift 2007 bar, and when I contacted a dealer, he proposed my to buy a new shift bar cause the costs of getting new lines would almost be the same as buying a new bar, think there was 20 Euro difference... I decided to buy a used 2006 shift bar and use it as spare parts - the rest will be sold as spare part on Ebay.de!
Also, I think it is a big issue that all manufactures only have information on products max. 2 years old - it is a big problem if one wants to buy used gear and there is no manufacturer information. Of course every company wants to sell the newest products, but, I believe, it would benefit the company to provide information about older products as well - they could highlight the development, new inovations, changes in design, material etc.
As an example: Try to find manufacturer information about a Wipika Free Air 16m2 projected from 2002, Takoon Scoop1 11,5 from 2002 or 2003 or Naish Boxer2 9m2 from 2004. I have managed because I flew these kites until early 2006 but it takes many hours on the internet.