Don't know if it is an error, but I just saw that on the USA Irix Site, the Blackstone (metal + WR/rugged) 15mm is the same price as the Firefly version (plastic)
475$ instead of 675$
BH has it foor 675$ also
free shipping to USA, insane shipping to Canada (123$), so I ordered it to be shipped to my broker south of the border...
Seems to apply to only the Pentax Mount, so I think it is a labelling error, so I did not take any chances and I ordered it right away as I was waiting for a good deal on the 15mm Blackstone...
Buy Irix 15mm - Blackstone - Pentax K
Hope my order would not be cancelled if it is the case, if not this is a super 200$ rebate deal !
Good luck !