that doesn't seem worth it since increased parts does just that. I remember using that on my first 1-2 journeys constantly to unlock everything super easily and it worked when coupled with high earning skills and collector
so am I, more parts=more supplies=faster unlocks.
Staring Ammo 153
Cheap Ammo 216
Cheaper Armor 188
Cheaper Purchase 180
Starting Small Firearm upgrade 179
Large Firearm upgrade 138
Increase Part Earning 182
I've only used one-time booster maybe about 30 times, if that.
I would have a lot more, if I picked missions that I could actually finish. Also the one I used the most (and is the hardest one to get) is the Large Firearm upgrade.
Best one-timer for Hunting Rifle users IMO