Watch List notes:

United Kingdom 2015 Gold Proof Set the five-coin set Five Pounds to Quarter Sovereign, the first gold set with the new Fifth Portrait FDC in the case of issue with certificate and booklet stating a mintage of only 350 sets, all apparently sold out by the Royal Mint within 7 days of issue at the issue price of £2,700

Estimate: 2200-3200 GBP