well lookingat it - english version here: https://www.felixprinters.com/shop/3...-3-1-assembled

It's an odd design. But would appear to be quite expensive for what it is.
As fara s I cna tell from the specification, it isn't using any special technology or partocularly expensive mainboard (running bog standard repetier, probably my favourite 3dprinter firmware, but capable of running on most low end boards).
Given the machines you can buy within that price range - you are not getting value for money.

The whole build plate attached at one end only, when there's an aluminium strut available to anchor the far side, is pretty weird.
It looks like it's designed to be easily portable - so that's probably why they've ramped the price up.

Would it be better than a $300 printer ? Probably - though that does largely depend on what $300 you've bought :-)
Would it be better than a $500 printer - doubtful, though the same: 'depends what printer' still applies.