When you're upgrading weapons nowadays you'll mainly focus on working with those iconic ones and the tier system basically runs everything. Starting with tier 5 stuff, you're looking at needing 75 components to push it up to 5+ which is already pretty hefty, but going for 5++ is where it gets serious needing like 200 components. The earlier upgrades aren't as rough though they do start ramping up pretty quick as you go higher.

The whole rarity thing is different now since they switched from the old common to legendary setup, and now it's all about those tiers 1 through 5++. Something interesting about this is that weapons that start at higher tiers actually save you some upgrade steps, but those final tier jumps are gonna cost you big time with components.

You won't be able to mess with tier 5 stuff until you hit level 33, and for the real endgame 5++ gear you need to be at 51. Maybe worth knowing there's this weird thing with some older saves where tier 5 upgrades might show lower costs than they should, but that's not really how it's meant to work. When you're planning your upgrades, definitely keep an eye on your component stockpile cause those high-tier jumps can clean you out pretty quick if you're not careful.