There's a buy one get one free (BOGOF) offer on all LeapFrog software at Toys R Us at the moment. Have a look if you've got any LeapFrog devices. For example, this would be a saving of £19.99 if you have a Leapster.
All you have to do is select two LeapFrog items. When you checkout, the cost of the lowest priced item will be deducted. This deal ends on the 28th of January.
Many of the software cartridges were out of stock for home delivery when I checked, although you could still get them using the Click and Collect option. That's only useful if you're able to get to a store though.
However, there were programs like Ben 10 for the Tag Reader and Dora the Explorer still available for delivery as well as collection. These titles cost £12.97 each so that's a good saving.
Thanks to Jas10 at HUKD!