Have you ever raided 3 moon dungeons in a row, only to end up with 3 moon buggy schematics?
It's not great.
I suggest adding schematic trades to alien villagers.
To keep it balanced, they will always demand a schematic of the same tier in return, in addition to some Lunar Sapphires.
Example Trades:
Moon Buggy Schematic + 2 Lunar Sapphires --> Tier 2 Rocket Schematic
Tier 2 Rocket Schematic + 2 Lunar Sapphires --> Moon Buggy Schematic
Cargo Rocket Schematic + 3 Lunar Sapphires --> Tier 3 Rocket Schematic
Ect.
This would add some bad-luck protection and make Alien Villagers more useful.
It's not great.
I suggest adding schematic trades to alien villagers.
To keep it balanced, they will always demand a schematic of the same tier in return, in addition to some Lunar Sapphires.
Example Trades:
Moon Buggy Schematic + 2 Lunar Sapphires --> Tier 2 Rocket Schematic
Tier 2 Rocket Schematic + 2 Lunar Sapphires --> Moon Buggy Schematic
Cargo Rocket Schematic + 3 Lunar Sapphires --> Tier 3 Rocket Schematic
Ect.
This would add some bad-luck protection and make Alien Villagers more useful.