So ridiculously easy and nice, I don't know why I didn't make it earlier.
Tiny Pocket Tank pattern has come in handy.
Fabric: 80cm mystery lace from Spotlight. I know I bought it on sale, but can't remember the cost, so lets say $15. It was probably much less.
Pattern: Tiny Pocket Tank - used plenty of times now = Free.
Bias: made from off white cotton scrap fabric
Thread from stash
Total: $15 - but probably much less.