They were easy enough for me to obtain, mostly because I don't use many of them. Here is my solution to this. Simply reduce the costs when infusing. Let me elaborate on this. You're not going to masterwork every weapon, just the ones you're using a lot, especially if it's masterwork is one you wanted. Range on that handcannon with dragonfly and rampage or stability on that AR with triple tap and kill clip, you want to use it. Here is my solution: Infusions cost less for the same weapon. I don't mean Tigerspite infused with Tigerspite, I mean ARs being infused cost less than an AR infused with an SMG. Sniper being infused with a sniper costs less than a sniper being infused with a handcannon. The cost goes down more if the archetypes match as well so infusing a 140 RPM handcannon with another one will be cheaper than with a 180 RPM. Finally, cores don't become relevant in infusion unless it's masterworked at 6 or higher.