Have you looked at the children's clothing at Argos recently? They have loads of great character clothing, footwear and accessories and many of them have big reductions. There are more than 100 items that are now under £5, and that includes t-shirts, pyjamas, slippers, accessories and footwear. Prices start at just £2.79 so it's well worth a look.
The slippers and pyjamas would be ideal for the Christmas Eve Box, and with prices from £2.99 these are cracking bargains.
There are also Frozen Slippers* for £3.99, an Olaf T-shirt* for £2.79, Frozen T-Shirts* for £3.69, a fab Star Wars T-Shirt With Cape* for £3.99, a Glow-In-The-Dark Minecraft T-Shirt* for £4.49, and even a full outfit with Peppa Pig Top, Leggings and Headband* for £4.99.
Stock levels do vary on some of the items, but most have plenty available for reserve and collect or for home deliver at a cost of £3.95.