Or- for a hundred grand less (one has to watch those pennies of course)- this seven bedroom manor house in Lingfield.
http://www.rightmove.co.uk/property-for-sale/property-36974175.html
Lindfield definitely looks a tad overpriced on the evidence of both the ones I've just found.
Same price buys you this in Cuckfield: Grade II listed, five bedroom house with additional two bedroom cottage, beautiful grounds, tennis court and fifteen acres of land.
http://www.rightmove.co.uk/property-for-sale/property-39911214.html
I think this would be higher up my list than the...
I presume it's a combination of
(1) Rarity. Lindfield village centre. Very popular village, & houses right in the middle can't come up all that often
(2) Big garden
(3) 6 bedrooms
Other than that, it does seem a little overpriced compared to large country houses you could pick up for that...