Quantity

Cost

1 £3.13
2 £5.75
3 £8
4 £10.25
5 £12.50
6 £14.75
7 £17
8 £20
9 £22.25
10 £24.50
11 £26.75
12 £29
13 £32
14 £34.25
15 £36.50