Obtaining the first round of life-prolonging treatment may be out of reach for the average people, but a Senior Mech Designer was never hurting for money.
Seniors normally spent an inordinate amount of time, money and resources to progress their research. At this stage in their careers, many Seniors valued their research over their companies. However, it took an extremely long time for them to obtain any breakthroughs.
Most never managed to achieve any breakthroughs in their lifetimes. Therefore, they diverted some of their efforts into earning huge amounts of money to be able to afford the first round of life-prolonging treatment from the MTA.
While expensive, a Senior possessed enough earning power to pay for the treatment within their lifetimes. Such expensive treatments were normally out of reach to Journeymen.