Did some testing and it turns out that there's a limit to how many times you can upgrade and item before the option disappears (~20-30 times). And the resource cost going up so quickly to the point where it costs hundreds (500) of one blue resource is ridiculous for the amount that you get normally though dismantling. I can see it being important at later levels (killed an nearly impossible enemy that dropped lvl 70 gear). I'm lvl 31 with 29.6 hours in the game spent focusing on gigs and it's been difficult in leveling up quickly. But there's absolutely no point in do so early game with its current resource cost. Heck it's better to find a newer current level weapon compared to upgrading your old one since the stats are better.