Using the examples given on pages 155, 163 and 167; I've taken it to be the sum of the individual weapon costs divided by three (rounding to one decimal place) and add the mount cost rounding this total up to nearest 0.5 MCr.

Does this look reasonable? Are the cost of the turrets for the Murphy/Beowulf examples a typo?

(I think the use of not all standard tech level in the Hybrid SLM components adds 0.5 MCr to the Murphy cost and 1 MCr to the Beowulf)

using Sandcaster base cost of 0.1 MCr, Beam Laser base cost of 0.5 MCr, Missile launcher base cost of 2 MCr

page 155, Basic (weapon costs / 2) VDistant (mount cost x 1) Barbette (3 MCr) : ((0.1/2 + 0.5/2 + 2/2) /3) + (3 x 1) = (1.3/3) + 3 = 3.4 MCr (3.5 MCr)

page 155, Modified (weapon costs / 2) Orbit (mount cost x 3) Large Bay (10 MCr) : ((0.1/2 + 0.5/2 + 2 /2) /3) + (10 x 3) = (1.3/3) + 30 = 30.4 MCr (30.5 MCr)

page 167, Standard (weapon costs x 1) Orbit (mount cost x 3) Triple Turret (1 MCr) : ((0.1 + 0.5 + 2) /3) + (1 x 3) = (2.6/3) + 3 = 3.9 MCr (4 MCr)

page 163, Standard (weapon cost x 1) VDistant (mount cost x 1) Triple turret (1 MCr) : ((0.1 + 0.5 + 2) /3) + (1 x 1) = (2.6/3) + 1 = 1.9 MCr (2 MCr)

This launches Short Range Missiles though I'm not sure why this isn't Attack Range - it doesn't affect tonnage or cost when the Beam laser and Sandcaster are VDistant?

Then pages 43 (Murphy), 45 (Beowulf) and 197 use a triple turret with various tech stage weapons

VDistant/AR (mount cost x 1) Triple turret = 1 x 1

Improved (weapon cost x 1) Sandcaster = 0.1 x 1

Standard (weapon cost x 1) Beam Laser = 0.5 x 1

Advanced (weapon cost x 2) Missile = 2 x 2

using the procedure above gives

(0.1 + 0.5 + (2 x 2)) / 3) + 1 = (4.6/3) + 1 = 2.5 MCr

but for the Murphy (page 43) and Beowulf (page 45) this is 2 MCr, have I misunderstood the examples?

The weapons/defences tables (pages 83 and 85) give the Hybrid SLM weapon system to be 1 MCr (+ mount cost).

Using standard weapons and the procedure above (0.1 + 0.5 + 2) /3 = 0.9 (1 MCr) which looks good (+ 1 MCr for triple turret).

p.s. I was looking at this to calculate a TL-12 Hybrid SLM along these lines

VDistant/AR (mount cost x 1) Triple turret = 1 x 1

Advanced (weapon cost x 2) Sandcaster = 0.1 x 2

Modified (weapon cost / 2) Beam Laser = 0.5 / 2

Ultimate (weapon cost x 3) Missile = 2 x 3

(((0.1 x 2) + (0.5/2) + (2 x 3)) /3) + 1 = ((0.2 + 0.25 + 6) /3) + 1 = (6.45/3) + 1 = 3.2 MCr (3.5 MCr)

Mod Triple turret Hybrid SLM-12 Attack Mount Mod=0, Defence Mount Mod=1, 1 MCr

Adv VDistant Sandcaster-12 Mod=+1, Hits=1D, R=07, 0.2 MCr

Mod VDistant Beam Laser-12 Mod=+3, Hits=1D, R=07, 0.25 MCr

Ult AR Missile-12 Mod=+4, Hits=1D, S=07, 6 MCr