The poundland shop sells a 1.5 kg bag of sugar for you know what a £1 is this a good price.
Sure is. My local Tesco charges over 90p per kilo.
My best price was 69p per kilo in Poundstretcher I think, not as good a rate as that.
Yes sure, just make sure it is not form genetically modified crops, and they put some fairly nasty stuff in to make it white (so I've heard). That is ok if you are over 10kg but maybe not if you are under 10g.