I think a -2 reduction on s.astromechs would be fair.
The point is that you would get the 'Salvaged Astromech (2 points)' for free, which allows you to discard a crit with the ship trait, which is comparable to the Integrated Astromech.
It's kinda similar, but nowhere near as good. It doesn't do anything if you don't take any crits, and doesn't do anything if you take a pilot crit. Where IA works anytime, so it's a guaranteed 1 damage blocked and gan be used on any crit.