Upkeep:
I'd prefer to have what'd I'd call active upkeep rather subtractive upkeep.
What I mean by this is certain advantages you get require continued financial expenditure, but if you cease to pay or engage in the appropriate mechanic then you don't receive the benefit, but you don't get "penalized" from your neutral starting situation.
For example living in a nice area gives you a bonus to specific type of social rolls maybe helps your rep, i.e. being a luxury condo in the "good" part of town in or der to live there you have to pay, however once you cease paying you lose the social advantage you gained by living their. So in the end your in a way paying for a temporary buff that periodically cost resources, but the buff relates to a in game decision that makes "sense" narratively and reflect the everyday mechanics that flesh out a world. Therefore you still choosing how to "spend" your money rather then having something "take your money." You're not put into a position where you feel you "have to spend money", but you are motivated to spend money and keep spending because it benefits you in a way that makes sense for your play style. I.E. I don't care about social stuff I'm happy to spend that money on more guns rather than enhanced social rolls.
2ndly A SMART system for cybernetics maintainance. Getting shot/fighting/and just living with lots of implants should demand upkeep.
> Repairing critically damaged cyber limbs
> Repairing scuffs etc. to appearance which cause you to lose social benefits to your "style"
> Homeostatis of implants, having four cyberlimbs should mean you have to "tune" your implants to experience full benefit of multiple cybernetic systems.
Cyber is expensive and it should stay that way not just in terms of buying costs, but the 'hidden' maintainance of implants. Deus Ex style you get it and it works perfectly except for an arbitrary "energy" mechanic is lame.