Also wanted to mention that I agree with Warl, that having a tech level based DP cost would be a good way to handle such things (as a DP cost for something like Tracking or Leatherworking should be higher for most professions in a sci-fi setting than in a fantasy setting (looking at it from a low-tech skill perspective).
actually, Not quite what I meant.
What I mean is that the costs don't need to actually change... Just what you can do with it at certain tech Levels does change.
For instance,
Surgery:
At a Low Tech Level, there isn't much to Surgery. It's Mostly butchery an With the Non-antiseptics of the time, and no anesthetics, More likely to Kill the patient than Help them.
At later tech levels... say 1980s, Surgery had gotten much better, with the additions of Antiseptics, antibiotics and anesthetics, One could, say remove a bullet, or even repair a Artery without much risk to the patient.
To day we can even repair the heart and do some brain and neuro work without to much risk.
50 to 100 years from now we may be able to do Brain transplants...
But that is all based on Tech Level... The Tech Level determines the Knowledge and resources available to preform such tasks.
A 2100 tech level person, without his Gear, in a 0 BC environment, Might not be as skilled as a 0 BC tech level person in a 0BC environment.
That way you can have Cross over Cultures ( this player comes from a lower tech culture than anther player) without having to effect the DP costs.