Real Techniques Base Shadow Brush: £21.99 from Boots or Superdrug (I know it sounds pricey but it's because you can only buy it as part of a set, but all the brushes in the set are worth having, in my opinion).
Bdellium Tools 776: £7.50 from Lovemakeup
I love Bdellium brushes, they are so awesome. They're really affordable and ALL of the bambu brushes are vegan (and the whole range comes in about 4 different colours).
Zoeva 227V Soft Definer: £5.95 from Lovemakeup
Firstly, this (and the bamboo winged liner brush) was the first Zoeva brush I've bought, so I thought it was super cute when I saw that it came in a little ziploc wallet. I think this will be brilliant for taking a few brushes with you when you're travelling.
All of these are great alternatives and work just as the 217 does. The major upsides of synthetic brushes vs animal hair, in my opinion are:
1. Obviously - 100% cruelty free and vegan
2. They do not absorb as much product so they are perfect for creams as well as powders
3. They wash up better than real hair brushes
4. They do not shed like animal hair brushes, which is something that used to drive me nuts.
Also, the MAC 217 retails for £20 in the UK, so all of these are MUCH cheaper options, except of course the Real Techniques Base Shaow Brush, but as I mentioned, it's because it's only available as part of a set of 4 brushes.
Did I convince you yet? ;o)
Do you know of any 217 dupes I've missed? Or there any other brushes you need a dupe for?