If it also has 120 munitions on it,which would put the total equivalent price to 550 mp plus i would say bullshit.When u make a trap,make a good one.
I'm not asking about potential side munition costs although they are possible.
And 340 mp unit with upgrade is still 340 mp unit, it doesn't suddenly become tank, 340 mp unit still is as survivable as 340 mp unit, weapon upgrade or not.
There are only 3 units in game that directly gain suitability from muni upgrade.