I picked these up in Tesco of all places:
Wheel of inkpads £4 - they come out individually so I'm sure to get in a right mess.
Stickers £3 - a couple of big alphabets, a couple of small alphabets and some mixed stickers.
Test tube embellishments £2.50 - butterfly beads, heart gems, mini safety pins, sparkly beads and flower sequins.
They also had packs of paper in the same range in 2 sizes. the small one was £2.50 with really cute flower designs and coordinating plain ones. Unfortunately when I opened it they were all shiny paper so will do for DD and it's gone in her Easter basket as I couldn't be bothered to take it back and know she'll love it.