If only Saiyan Z were here. He has a few different formulas to use to answer your question.
It would all depend on your overall def and stats, not just one little piece of armor. I think it would be best to show you an example of a few things. I'm no expert in bot builds, there is always a 'different' way or something. So don't take what I'm soon to say to heart.
For reference,
Armours will be set up like (def,str,str+,dex+,con+,int+)
Weapons will be set up like (min,max,str,dex)
Final result will be set up like (str_total,dex_total,con_total,int_total,min_final,max_final,total_hp,absorb,block_percent)
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To start out, I think it would be best to start at the smallest scale I can possibly think of
Level 26 - Rushed Scarabs.
Scarabs(32,45,60,58) : 60str, 60dex, 10con, 10int.
Demonhide Armor (130,50,0,0,0,0)
Death Mask (70,60,0,0,0,0)
heavy bracers (38,58,0,0,0,0)
sharkskin boots (33,47,0,0,0,0)
Rushed Scarabs (60,60,10,10,51,72,150,32.92,5)
Now if you sacrifice 1 point of dex, for one point of str, to get better armor
Level 26 - Rushed Scarabs(2)
Scarabs(32,45,60,58) : 61str, 59dex, 10con, 10int.
trellised armor (140,61,0,0,0,0)
Death Mask (70,60,0,0,0,0)
heavy bracers (38,58,0,0,0,0)
sharkskin boots (33,47,0,0,0,0)
Rushed Scarabs(2) (61,59,10,10,52,73,150,33.52,5)
The min and max damage both raised up by one, the absorb raised by .6.
It is a subtle change, but enough to sway a battle.
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Level 40 - Conned Scarabs
Same as Rushed Scarabs, yet with 68 base con.
Connned Scarabs (60,58,68,10,52,72,730,32.92,5)
Level 40 - Conned Scarabs(2)
Minus one con point for one point of str
trellised armor (140,61,0,0,0,0)
Conned Scarabs(2) (61,58,67,10,53,73,720,33.52,5)
The final Damage of Conned Scarabs would be (34.57,48.53)
The final Damage of Conned Scarabs(2) would be (35.55,48.97)
Min damage difference : .98
Max damage difference : .44
Now, this one has 10 less hp, but .6 more absorb. The .6 absorb has a minor effect on the min and max damage of the Conned Scarabs.
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It gets to a point where there more of an optimal build and making a change to str,dex,con won't do any better. I'm not sure when this actually starts to change again. I'd say somewhere around level 180. You have tournament builds, that are the most optimal for a certain level, 132 souls, 142 souls, 119 plasmas, 80-105 answerers. You have cs builds, that can be rushed to gain that certain weapon, totally sacrificing con. When I make a leveler, I usually don't worry about the optimal build because I'm only fighting trainers or crappy ratio whores. Since, I've never made anything over 146, I'm really no more help.
-Alan