Not come across the Mitre Wizz yet... I think the general benefit is that these spacers are supposed to be chunky enough so that they dont get lost during tiling.
The main sellin point being that
standard spacers can either slip down the back of tiles if they tile had to be packed out, or left in situ by mistake and grouted over.
Also the point about solving having to fiddle about trying to prise them out of their slots because they are not proud of the tile rather they are flush or recessed.
Easy for fat fingers to yank out. Those things seem to make a bit of sense to me (But hey waddo I know) !!
I will chat to him about the price. What footprint would 250 take up? Probably about the size of a shoebox.
Maybe a price of £19.99 for the set would bring the cost down to 8p and be sensible ??