We ploayed one game of Starmada using Expendable Weapons:  We quickly decided that they were too powerful for their low cost.  I think the cost multiplier of .2 is too cheap, .5 would be more reasonable, considering the design my friend brought.  Here it is:

Shadow Zone BREAKER class
CR=130, Hull=10, Armor=0, Thrust=9, no shields, no ECM, stealth, etc.
Here was it's only weapon; a brutal expendable weapon:
Death Matrix
Arc=FR, Range=6, it has {Acr,Cts,Dx2,Dx3,Exp,Sct},  Attack Dice 16-11-8-6...

My friend kept this ship just out of range 18, which is the maximum range we limite ship-weapons too.  Then the turn he won innitiative, he overloaded the engines of this ship and charged to range two of my largest Four-turret DN.  This DN has 31 Ablative Armor & 46 Hull, with a cost of 515.  He fired and vaporized this larger DN
I Calculate that at short range this Breaker class ship should, on the average, do 33x21=681 points of damage.  If he had split his fire, he could have Destroyed all ships on my side with one shot. :!:
Have I miss calculated? 
This quickly led us to rapidly agree that expendibles are broken, Very Broken.  No disrespect to the S:NE designers, but I think y'all underestimated the potential power of the Exp Weapon Trait.
Have other players used the Exp W.T.?   How did it turn out?
We are playing S:NE this afternoon w/o the Exp W.T.

I have designed expendable for the Andromedans (in my Star Trek adaptations) but made their transporter bombs not really powerful. Maybe that's one more problem with designing your ships the way you want. It can lead to abuse...

Marc

I play with BeowulfJB and that person made this NON-Exp ship:

Shadow Zone ASSUALTER-class Deathrider  (141)
ARMOR           
HULL    [_][_][_][_][_]  [_][_][_][_][_]   [_][_][_][_]
THRUST    [9][6][5][3][2]       WEAPONS    [_][1][2][3][4]
  ECM    [_][_][_][_][_]        SHIELDS    [_][_][_][_][_]
   Fragile Systems
  WEAPONS                                  ARCS    RANGE    ATTACK DICE    -4         -6         -8    -10
4× Blackhole (Acr/Cts/Dx2/Sct/Slw)    [FR]    2-4-6             12    8    6    4    3    2    2    1    1    1    0    0

All he did was take off the Exp, Dx3 and 1 damage die. It is only 11 more points but still very effective. :!:

We are discussing how solve ships like this. Bigger ships are not the key. Any help for us here in Jacksonville?

i like the idea of allowing weapons to only have one damage modifer from {Dx2,Dx3,Cts}. 
:idea: Also, we could only allow Sct,Dfs,or Tls on weapons that don't have a damage modifier; or is that going too far?

Sounds good.  Not sure if my gaming buddies will go for it tho. 
Another solution is to manuever more carefully.  I usually play one c500 point DN and some destroyers.  On turns when my friend moves and fires first, I will move the DN last, and keep it out of the narrow arc of destruction of my friend's attack-ships.  In fact, I can move it into a position where it can fire its range 18 weapons and pick off these smaller attack-ships.  This could work too...