I would say stamped as well.
I'll give some overall prices, but if you're selling at UK Ponycon, they will probably sell higher (because of the £,no shipping, and that people can see them before deciding).
Spanish Moonstone - $20-25 if NC, more if Spain marked
Italy Blossom - $8-15
Italy Heart Throb (alas with a pen tattoo on her non-display side) - depends on how bad, but ~$8-10
Italy Peachy (2 stamps) -$3-5
Italy Parasol - $8-12 if normal hair
Italy Cotton Candy - very much depends on how pink
NC Mummy Apple Delight (with one eye scratched off and some pen marks) - ~$5