Let's tackle the big questions....
*Please remember that the info below is intended as a guide*
The cost of your cake will be determined not only by the size, but also by the flavour you choose, any special dietary requirements, and most notably by the complexity of the design.
When it comes to portions.... it depends how big you cut the slices!
The portion sizes below refer to cakes with 3 layers of sponge inside.
Portions
6"/15cm 10-20 portions
7"/18cm 15-30 portions
8"/20cm 20-40 portions
9"/23cm 25-50 portions
Single tier cakes
  6"/15cm from $230
7"/18cm from $270
8"/20cm from $310
9"/23cm from $380
Two-tier cakes
  6" + 4" from $265
7" + 5" from $380
8" + 6" from $470
9" + 6" from $540
9" + 7" from $590
Multi-tier cakes
  8" + 6" from $470
8", 6" and 4" from $600
10", 7" from $660
9", 7" & 5" from $725
10", 8", 6" & 4" from $900