Second weapon cost

[MrGray]

I am looking for the rules relating to the purchase or cost of a second (or additional) weapon. Specifically, a character builds a unique weapon like a multi-function pistol. The character has a back-up or second weapon of the exact specifications. I looked in 5E under Multiple Foci (p.190) but did not find what I need. Yet in CK&C (p.39) under Warbird, the character built a Wrist Rocket (right hand) unit for 30 points (60 active points) then has a second unit (left hand) for 5 points. Second example, same source (p.27) the V'Hanian Hovertank. Secondary gun for 18 points (45 active points) then "total of 4 Secondary Guns" is 10 points.
Second part of the query, if the second weapon is not a backup to the first but a true second weapon does that effect the cost. If I built two multi-function pistols and have Two-Weapon fighting with Ambidexterity (etc., etc.) to use both weapons simultaneously does the second cost the same as the first or is it built at a reduced cost as above examples.

[fbdaury]

As per the FREd, any secondary foci are bought at the cost of 5 points per doubling of foci. This is found in the weapons/armor section I believe. As to the second part of the question, the weapon still costs the 5 points and allows for multiple power/two weapon fighting attacks- personally I think multi-power attack is the better option due to less overall penalties.

[MrGray]

If a player purchases his weapon as a multi-power such the MP is listed as the gun .. Desert Eagle .50 w/ OAF, STR minimum, STR can't add to Dmg, Beam, Jamming, RSR to change clips ... then buys the clips as his slots ... RKA AP, RKA x2 KB, STR Drain, NND KO gas each with a 8 charges and two clips. There seems to be a problems with this but I can't wrap my head around it. HELP!
Once all this is done then he buys a second MP for 5 pts. Is the legal?

[fbdaury]

IN a nutshell... yes. A multipower that is all in one weapon can all be taken away at oe time, so there is an upside/downside effect there. Any second weapon costs on;y 5 pts. -don't hurt hurt yourself over it, just go with it...