Judith in England wrote:

Are you are saying that roundup in apparently the same bottle and packaging is
sold in "bargain shops" as a less effective solution - watered down or
different make-up?

Not specifically "bargain shops"

Are you sure they do not have a different name (type of Roundup) on the labels?

I'm sure they *do* have accurate info in the small print, but the
headline label doesn't tell you whether the pack contains 7.2g/ml,
120g/ml or 360g/ml, they have several different phrases for the same
strength (Ready to Use, Concentrate, GC, Ultra 3000, XL, Super
Concentrate) and of course multiple container sizes and types.

Confusion marketing, though not to the extent that e.g. one shop sells
300g/ml slightly cheaper than others sell 360g/ml.