How much do real MK18s/Select Fire ARs cost for dealers, Military forces, Police forces, etc. per unit?

[Luna]

Just a logistical question I’ve always wanted to know but can’t find a solid answer. For example how much does the military actually pay for an M4? I saw $650 or about on a google result for FNs contract per M4, but what about an MK18 or 416 for SOCOM cost? It can’t be much more than civilian counterparts or equivalents since there really isn’t too much of a difference and a seat/3rd hole isn’t really a materially expensive thing. Just looking for a number on how much a brand new, straight from the factory, Full Auto AR (MK18s and 416s to be specific, or a solid number on M4A1s and such) that a Military unit would pay for one