I just got Heart of the Empire for Christmas and I do not understand the section under Figure Cost on page 4.

Each Figure in Imperial Assault has a figure cost that may be references by abilities and game effects. A figure cost is one of two values.

- If a deployment group has the starting group size of 1, that figure's figure cost is equal to the group's deployment cost.

- If a deployment group has a starting group size of 2 or more, each figure in the group has a figure cost equal to the groups reinforcement cost.

I have no clue what they are taking about here so any help in understanding would be appreciated.

It's exactly what is says. Figure cost may be referenced by abilities and game effects, such as
a) skirmish scoring and
b) Murne Rin's False Orders ability.

If a group has only one figure, the figure cost is the same as the deployment cost. If there are more figures, the figure cost is the same as the reinforcement cost.

If you don't have an ability referring to figure cost, then you can safely not understand what figure cost is.

Ah okay that makes sense I thought they were changing deployment costs or something.