Since the BT shop deal has now expired, I thought I would list this for anyone still trying to get this white hue kit.
Its available on amazon.es for 56 euros: https://www.amazon.es/Philips-Hue-White-interruptor-controlable/dp/B016H0R7SE
I purchased at the weekend and delivered (w prime) its approx £53 when bought on a card that gives free non-sterling transactions.
I paid E62.32 inc delivery = £53.03 charged to me.
Mine arrived in 2 days (pretty sure it was fulfilled from UK tbh).
Its european plug, so you'll need to buy a converter. Definitely dont use a screwdriver to force the euro plug into your UK socket ;)
This is for E27 euro screw-in bulbs, but E27 to B22 (bayonet) converters are available from Ikea, ebay etc for peanuts.
Not quite as cheap and the BT deal, and no quidco, but still cheaper than RRP (£59.99).
I think these might be the last remaining stock from this model, and there is no sign of anything else at this price point from Philips.