Electric reels a great idea but I would like to know why they are so expensive
I don't think any of us can give you the exact reason or reasons.
But I would say that this is a typical example of
economies of scale principles.
Added to that are other factors like manufacturer profit margins and what the acceptable perceived value of an item is in the market place. Shareholder demands are another contributory factor.
My perception is that these items are more popular in the USA than anywhere else. The Americans have a different view of the value of mechanical items. For example, American finance houses still repossess 15 year old vehicles they have a title on (watch the Reponut channel on YouTube) where we in the UK have been hoodwinked into believing that a 10 year old car is worthless.
Added to that would be import duties for manufactured goods outside the EU, transportation costs for limited quantities and UK supplier markups.
One of the things I would especially like in a motorized hose reel is one that has an automatic layering system. The last time I looked, these were being marketed in the US for around $3000.
When Nat Jones in Ireland was window cleaning he spent a lot of time working on a motorized hose reel with a layering system, but it never got off the ground for lots of reasons. I still believe he has it on the proverbial back burner for a future project.