Prototype

You can't get Bumblebee's hardcopy in the market NOW! Woh!!!

A prototype is a sample of a manufactured object produced for internal use in the manufacturing process. Various sorts of prototype exist:

• Test shots, products of the actual production tooling
• Hardcopies, preproduction casts which are usually resin and often have very sharp detail
• Mockups, rough models used to prove a design, which may be significantly different from the finished product

Prototypes may be virtually identical to the finished product, or they may not. Frequently they are a single color of plastic. Some are completely or partly made of translucent material, which looks like delicious candy and helps the designers observe the functioning of hidden parts.

Not for sale

Prototypes are not offered for sale, but they sometimes find their way out of the factory and into collections, which is certainly through theft, unless it isn't, which would make the collecting of them unethical, unless it's not.

From Teletraan I: The Transformers Wiki, a Wikia wiki.