After buying the EcoTools 5 Piece Brush Set from eBay and writing a post about it here, I ordered the Bamboo Bronzer Brush. I bought it from here and it cost £4.96, including P&P. Boots are selling it for £9.99, so that's quite a saving!
It's big, it's chunky and it's very soft! It also washes well.
After talking to a few people and comparing my brushes to the ones in Boots, I think the eBay ones are real. Even if they're not, they're great quality!