Centaurea cyanus 'Blue Boy' - Cornflower - can be bought in bunches of 50 stems - cost around £30 max. I could put you in touch with some British flower growers - you may be able to negotiate prices yourself and want to use British grown?
Helleborus purpurascens - Often the first flowers can be seen low to the ground in December (usually before the new foliage appears), but they continue to open as the red-spotted stems grow, right through until early spring. A variable but very pretty deciduous clump-forming perennial that makes excellent groundcover in partial shade.
‘Ivory Prince’ Helleborus hybrid ‘Ivory Prince’ has dark red-pink buds that bloom creamy white and age to a mix of burgundy and light green. Blooms Opens creamy white from late winter to early spring Size 12 to 15 in. tall and wide Cold-hardy USDA zones 4 to 9 Heat-tolerant AHS zones 9 to 1 Source Plant Delights Nursery, Inc.