Inspiration: Doctor Who Oxygen
The Doctor, Bill and an angry Nardole travel in the TARDIS follow a distress call to a deep-space mining station. When the TARDIS is jettisoned by the station's computers, the trio are forced to wear "smartsuits", robotic spacesuits capable of independent operation tied to the station. The suits are also the only source of oxygen, as the mining company does not provide an oxygen atmosphere inside the station, and every activity is measured in breaths. The surviving crew warn them that some suits have received instructions to "deactivate" their "organic components", killing the wearer via an electrical discharge but remaining autonomous. This signal can be carried by touch, which has caused most of the crew to be turned into zombies, enslaved to the suits' programming. The Doctor and the others plan to walk outside the station to an uncompleted portion not updated in the computer systems to hide. Bill's suit malfunctions during depressurisation and forces her to remove her helmet. To save her, the Doctor gives her his helmet as they spacewalk. He survives the vacuum of space, but has gone blind from the ordeal.
The computer discovers their location, and Bill's suit again malfunctions and will not move as they flee. The Doctor leaves her behind, assuring her she will not die, but she is electrocuted when they touch her. The Doctor reveals the limit of breaths is an algorithm to stop people "wasting" oxygen, part of the company's automated profit-making system; killing the wearers was just the logical endpoint of corporate profit over human life. He hacks the station's systems to cause the station to self-destruct if they are killed, and convinces the others this is a "good death" and revenge against the corporation. The computers recognise this threat and recalculates the suits' programming, and the zombies turn over their oxygen supplies to the survivors.
I haven't kept up with the Doctor in a long time, but rumours of this storyline made it irresistible.
So what you do is just turn off life support, and live if not continuously, mostly in your spacesuit.
That pesky overhead goes mostly away, and you only have to pay for what is actually used.
Half the savings could be used to discount the passages.