You could make this one quite simply.
Print off your pictures of butterflies and varnish them with PVA glue. This will keep them rigid and intact for longer.
Add a small clear bead to the back of the butterfly.
By a cheap silver wire necklet like this
Take the end catch off the necklet, thread your beaded butterflies on, solder the end catch back on (doesn't need to be perfect as it's at the back.)
Taadaa. You've made it yourself for less than £20.
(Really I should have just kept this to myself and flogged it to you
)