Yes, this Bubbles Necklace is whimsically cute. Is it £300 worth of worth of cute? In my opinion, hell no. Enough people have apparently disagreed with me that there's only one left, though, so perhaps I have a warped sense of value. Or perhaps these particular shoppers fall into that category where money > sense.
So, here's what I propose: Buy a bubble wand and some chain. Gild wand. Attach to chain. You can thereby successfully "awaken the child we each keep inside" without spending £300 to do so.