From their announcement:
Hello, we have another special offer for you, this time in our painted mini selection. For a limited time only you can Buy One Painted Miniature and Get the same priced or cheaper one for Free.
This goes for each painted mini you put in your basket, you can put another same priced or cheaper in for free.
You will be charged at checkout for all the painted minis, but we will refund in full through paypal the cost of the free same price and/or cheapest painted mini/minis.
All the minis have been professionally painted, most have been personally painted by Bob. These are real bargains and there’s only one available of each so be quick, before they’re all gone.