Surprisingly it’s actually not, on most sites its cheaper to get a new FD7000 or 8000 than it is a 5700. But mostly cos I’m dumb and am rushing a bike build. Realised it’s a no go and I have once again learnt a good lesson
i have a collection of band on 10spd front derailleurs, all 5700 era if not actually 5700, £15 each but have to wait for after xmas which you probably don’t want to
But why? A new 5700 FD should be really cheap