afresh the ikea circus tent that nocuts mentioned is offer of the week at my local okra at the moment so down to £9.95. And if you use your family card or create one there if not already signed up, scan the receipt and you can win something - think everything scanned wins - could be a free donut or a family holiday to Sweden or something in between!
** It's worth signing up to the Clarks newsletter as they often have different offers on.
Likewise the Brantano website/newsletter - they had 25% off everything in the shop in the summer holidays which was fab for school shoes. Think they have a sale on at the moment but it's selected stuff rather than anything.
Haudyer is it worth looking for one of those stamping letters kits so you your DC could stamp the bags? I think hobbycraft had a set for £5 instead of £10 at the moment. Or look on eBay and see if there are any good ready made stamps (or indeed bags) that are cheap.