Yes you are right it IS insane. OK it’s an 85 so I presume you aren’t doing a concourse rebuild. Well maybe you are but you’ll get over it. The reason they are so expensive is there are so many types of decals & they have to print in large quantities so they have to store in large quantities & it becomes a logistics nightmare & the freight importers distributors & bike shops all have to have a markup so there you go.
Here are your options.
1. Buy any old stickers you can find & slap em about with reckless abandon, they’re only going to get ripped off on a bush anyway.
2. Buy a Troy Lee designs or whoever designer sticker set that won’t really suit a non radiator bike & cost silly $ anyway.
3. Go visit the local auto computer label shop who will probably already have several Kawasaki labels which won’t be original but a damn site cheaper.
4. Grin & take it where it hurts (the wallet) at the Kawa store. If you never ride the bike again it might be worth big dollars when your grandson sells it.
Make the right decision & save the money to replace the knobblies more often, you’ll enjoy it more.