Use 'a pig of a something' to describe tasks or situations, not people or animals.

Contextual Use

Express frustration or dismay with how difficult or unpleasant the task is.

Emotional Frustration

Do not use this phrase to describe people, as it may be considered rude and offensive.

Highlight the strain on financial resources more than technical difficulty.

Link the phrase to things that require a disproportionate amount of resources.

Recognize 'pig' here is a metaphor for greediness, where resources are 'eaten up'.