Just a real quick generalized Rookie vs. Sigma Xwing math problem:
Rookie = 21 pts.
- 3 (Subtract a hull upgrade)
- 2 (Subtract a targetting computer)
+ 1 (Add the cost of the ability to use the evade action - cost equivalent is the MF title card which does just that for the yt1300)
+ 2 (ability to barrell roll - closest cost equivalent is the expert handling EPT, although this doesn't create stress...)
+ 4 (ability to roll an additional attack die - closest cost equivalents are expose and opportunist which allow you to do that and are both 4 pts, although this doesn't have either of those negative effects of stress or agility reduction...)
+ .5 (for 1 pt. in pilot skill - cost equivalent of half of the VI boost of 2 PS for 1 pt.)
Sigma = 23.5 pts. (doesn't account for the additional cloak action ability and the lack of negative impacts of barrell roll and attack die boost - so the real question is, how much is that worth? do you feel that's worth more than 1.5 pts? that cost-value question is a good one.)
Personally, I think the base Phantom is costed pretty spot on. Maybe you can make the arguement it may be a point undercosted so the base Sigma should be 26 instead of 25. That may also be splitting hairs. I have no problems with the 25 pt. base, at all.
Now, the real question of cost vs. value comes from the upgrades...and that's where it becomes a lot different to guage real vs. perceived value.
You are forgetting to add in the cost for the Phantoms crew and system slots. Neither of those are free when costing a ship. And I think the increase from 3 to 4 attack should be costed more like the HLC rather than Expose or opportunist, more than 4 points for sure.
You could probably call the Xwings Astromech slot and the Phantom system slot a wash, but you can't ignore the crew slot, that is worth at least 1 + the modification opportunity cost (Bwing E2 title).
When comparing the Sigma with the Rookie, ask yourself in a vacuum, which ship would your rather take to the fight. 90% of the time the correct answer is the Sigma, it's just flat out a better ship. Choices that closely costed should be much more difficult.
ok, that's fair and that's what I was trying to point out with the upgrades. you've got crew instead of astromech, system instead of torpedo. both of those are more valuable on the phantom in a vaccuum, but still very different. the reason those slots are more valuable though, is because the cost-value of what you can put in those slots currently is better, not really the worth of the slots themselves. this can easily swing back to value nuetral with new droids or upgrades that take better advantage of the torpedo slot or whatever. the value difference actually comes down to the current options between those slots, not the slots themselves. that'd be my arguement, anyways. you don't want to cost penalize something just because the current options are slightly off balance that you have to pay additional cost for anyways. i do get what you're trying to say though.
the HLC-ish cost of the attack die upgrade I can see, but there are still additional positives that way, as well. so, split the difference, and say the value of not taking stress or reducing agility is another point or point and a half? that now puts it cost neutral now with the only thing not figured in is the cloak ability cost. That ability kind of has it's own self nerf in that it doesn't allow you to attack for that round and also takes your action to do it - so no dice mods on the roll. then gives the positional advantage the following round. pros and cons on both sides of that coin evening it out. still, it's an aditional abilty that should cost something, for sure.
Also remember that EH also removes target locks from your ship on top of the barrel roll.

