An average simply adds up sale prices and divides by the count, so one large renovated house or one rundown flip sold that month can swing the number without reflecting the typical Mayfair home at all. A benchmark is built specifically to resist that distortion.
Mayfair itself does not have a separately published benchmark, so the most defensible way to price a specific Mayfair house in 2026 is against its own direct comparable sales, adjusted for lot size, condition and any permitted updating, rather than against either citywide number.
That is the difference between a headline figure and what a specific house is actually worth. Get your hand-reviewed valuation from Joel Dyck.