I'm not a huge Coffee drinker myself but think this is a really good deal for convenience sake.
My local Tesco in Dundee are currently selling boxes of Kenco Fusion coffee for 89p which is half price as it is, but on the front of the box you get a coupon for 30p off your next purchase.
There are 10 sachets in a box and the deal is valid for the 2 in 1 (ie Coffee and milk) as well as the 3 in 1 (coffee,milk, and sugar)
I keep these in my pocket at work and find them to be very convenient as there's no need to buy in milk etc, and IMO the coffee tastes quite good too.
So with the voucher off your next purchase they are really costing 59p for 10 x sachets.
I'll let you do the Maths (hee-hee)
PS the money off vouchers are valid until 31st August 2008