I would spend that, but DS1's bedding is still looking good, and I don't need to replace it. But if I did, I would be happy to buy it from Laura Ashley or the White Company. I like the JoJo range of bedding for children too. And John Lewis. And Designers Guild.
DS1's bedding is from Dunelm. He has a dinosaurs print one (I don't think they do it anymore) and a city scene one, and they were £7.99 each to include a pillowcase. They're lovely quality, and habven't faded at all. Really nice, even 2 1/2 years on and they've each been washed at least once a week in that time.
Bedding for our bed is from Laura Ashley and I am 100% happy with the quality of that too.
Have you tried TKMaxx?