[Suicide Junkie]

Hrm, well. I can't remember exactly what happened with the negative cost components, but I do know that the only way to give a vehicle negative maintenance is to add a >100 maintenance reduction ability to a ship/base with a positive cost.

Making the inital BTGs cost zero minerals, and the extra ones cost plenty of minerals would be almost as good, though. It would get the same idea across, I think.