I recently bought 2 boxes for $96 from Colormix in Mongkok. I've seen prices range from $58-$56 per, but most promos I've seen are $96 for 2.
While I was at Colormix, the lady introduced me to another brand that is "one step up" from My Beauty Diary and they're called My Scheming Beauty (terribly silly name, I know). They're also made in Taiwan with similar function and ingredients, but I personally found that "Scheming" is much better than "Diary". It's wetter, and I find the results lasted longer. I am currently using Sake-kojic Extract (rice wine) and Sakura Whitening... give it a try! The Sake one leaves a nice tingle.
Bonus that they have English descriptions on the back!!
$100 for 2 at Colormix in Mongkok.