It looks as if the "sold price" is the "hammer price" plus the buyers premium but no VAT. I've come to this conclusion because if you divide the "sold price" by 1.1 the result is a round figure ending in £50, £100 or £1,000. Not done this to all the lots but enough to satisfy that myself that the results are consistent.
Hammer price £8,000
Buyer premium £800
VAT on premium £160
VAT on APC £1,600
Total £10,560