Happy Holidays
If you aren't battling the corrupted and saving space yet, the entry ticket fee is at its lowest during the Steam Winter Sale at 85% off (and the Soundtrack too, at 80% off.) which is the lowest values allowed before hitting invalid values for certain currencies.
If you're already in the fray and taking on the Simulated OMEGA corruption, then feel free to get a copy for a friend-- especially since multiplayer features are coming in the future~!