Maybe it's a temporary glitch.
But if not, I wonder if it was only ever there in tiny numbers to create a buzz? The 'value' was noticeably so much higher than the other two kits, it surprised me that the price was almost the same.
Maybe from Liberty's POV, the other two are the core of the promotion and the third one was just an attention-grabber/loss leader, helping pull people onto the site. Then once it's sold out, they're hoping shoppers with FOMO will panic-buy one of the other kits that costs a bit less to produce.
... That, or I'm a beauty-kit conspiracy theorist who should really be getting on with some actual work