The Makery also sell everything you need including the soles, but being a bargain hunter I did a little googling, to see if I could find any soles on sale, and found that New Look had these sandals for just £3
As I'm often between sizes I ordered a size 6 and 7, and even with delivery was still only £9.99 !
The only downside to my money saving idea, was unpicking the new look sandal, and not having a pattern, which is provided with the prymm sole that The Makery sell.
There is a free pattern here although the prymm one is probably better as it's designed for their sole. I decided to make my own pattern as I have wide feet and thin ankles so have a nightmare with shoes.
Here's my test version....I have identified I need the size 6 but a few stitches at the heel makes these wearable so I'm ready for the beach. I think on the next pair I'll make the heel fabric a bit higher and the foot part smaller but they are really easy to make, I never hand stitch anything if I can avoid but I really enjoyed sewing the blanket stitch around the edge was very simple to do.