The UK 2015 coin yearbook lists this coin as £3250 in F, and £9500 in VF. There is no listing for EF. The seller states this coin is "about EF". (This always strikes me as a little cheeky). I read somewhere that as a rough rule of thumb coins doubled in value with each grade increase, with variations due to scarcity in specific grades etc.
If this seller bought it for around £10,000, this seems to suggest that the grade is VF+.
I am very much a beginner, especially where gold is concerned, so would appreciate reading some expert opinion.
Regardless of the coin's actual grade or value, it is still a beautiful thing to look at.