I popped along to my local Tesco and spotted Piz Buin sun lotion half price. Most of the lotions are included in the offer including the One Day Long (which my partner uses and is very good).
I think this is a nationwide offer as I went into another Tesco yesterday and the offer was on in there too. I stocked up ready for my summer holiday. Bought a couple of Piz Buin One Day Long lotions for £6 each (RRP £11.99) and Piz Buin Tan Intensifier lotions for £8.50 (RRP £16.99)
Of all the lotions I've tried, I haven't been able to beat this brand for quality.
It doesn't appear to be on offer on Tesco.com. Not sure of expiry date.