I've heard reports that Right Stuf has refunded VAT for partly canceled orders on Special request by the customer - but the refund is based on the actual amount Fedex paid for customs. So currency fluctiation may change things...
No guarantee on this.
As books are zero rated in the UK, Right Stuf shouldn't charge VAT for these...
Afaik Black Friday and Christmas sale are more or less the same, with prices increase by about 3% for each item in the "second week", but additional items added every week. And as large orders are cheaper "per item", for us overseas customers the wider selection is better...
...but keep in mind that some items might become OOP.