Yes, they're 100% the right ones.

As for the price though, i'm sure you can get them cheaper than that. I bought mine from:

http://www.part-box.com/ford-20.5mm-rear-axlehub-spacer-set-2-spacers-with-bolts-p-20336.html

With the 12.5mm ones being here:

http://www.part-box.com/product_info.php?products_id=20334

One thing to bear in mind is that the bolts are too long for the Fiesta ST so you have to hacksaw about 8mm or so off. Not very difficult to do though.