There are various various minions in the game with a variety of attributes. Some also have unique interactions.
Minions have several technical details that need to be considered when creating a replacement.
Some minions are classified as a terrestrial creatures and some are flying/floating creatures
Minions can have unpredictable scaling, but are usually 1 to 1.
Minions tend to have a small list of movement animations.
Minions are generally the simplest creatures to edit.
A minion replacement is a unique and one of the simplest creature replacements which has a single core category of components.
Model
Textures and Colors
Skeleton
EID Binders
Core Animations (considered all one component)
Idle
Movements
Idle Ability
When thinking about what kind of creature you want to use for a replacement, think about some details about the creature.
If it's a terrestrial creatures, does it have a movement animation? Some terrestrial creatures, like Menphina with Dalamud, are stationary and thus do not have movement animations necessary for a terrestrial creature to appear to be walking or running. This is usually not an issue for floating/flying creatures that can get away with using their idle for movement.
Minion replacement mods are an advanced asset replacement that can be difficult to calculate a price for. Estimate to be quoted $5 for each core component.
For a full Minion replacement expect to be quoted around $25