GW have today announced 3 “Artificer” brushes for £42 (or £14 and £16 pounds for each of the larger two which can be purchased separately, as well as the £12 for the smallest, which can already be purchased; so the bundle isn’t even a saving). Their claim is that these are:
“the best brushes money can buy”
This presumably means that they’ve had Winsor & Newton produce them on their behalf and that they are comparable in quality to the Series 7 range, however, you can get Series 7 in similar sizes (with more options) for less than £10 each online so please don’t get suckered (the same goes for the other tools GW sell). Another good brand is/used to be Raphaël particularly Series 8404, which cost £1-2 less than Series 7 but I’ve heard rumour that their quality has gone downhill since changing factory location and they can be hard to get hold of outside of France (see my comparisons of Raphaël and W&N Series 7 brushes here). I also recommend Rosemary & Co., which I’ve started using myself as they are pretty similar in quality to Series 7 but for only £5 or £6 a brush and with a greater range of shapes.