"Economically viable" is not a concept that even applies here. There is no profit to be extracted on Mars besides raw resources, and it will basically never be profitable to ship raw materials between planets with chemical rockets.
Any hypothetical money to be made on a Mars colony will take generations to become apparent.
However, the technological advances required to build a Mars base and put humans there is within our grasp today. The developments associated with such a program would be of incalculable value to humanity, but are not directly monopolizable and monetizable in the immediate term.
So, no. It will never be economically viable to go to Mars because that question makes no sense. It would make economic sense to invest in asteroid mining because there are returns to be seen within your lifetime. There will be no such returns from any planet-based colony for a long, long time.
> The developments associated with such a program would be of incalculable value to humanity
Compared to what? The cuts to medical and other research necessary to pay for the incalculable money pit that Mars exploration is? In fact, fund research that has some value for humanity now and some of it will be useful for planetary missions in the future, whenever it's possible to do it without strain.
It's insane to waste public money on boondoggles for billionaires, they can fund their Mars missions themselves. Bon Voyage!
It's expensive to send anything into space, let alone make it to Mars. Chemical rockets are not cheap, even when you can recover the boosters and refurbish the engines. Comparatively, even visiting Mars makes a moon mission look like a cakewalk.
Genuine question; what even would make going to Mars economically viable? It we mean by economically viable something like "when the amount of wealth we generate, where wealth is stuff that makes the lives of humans better, exceeds that which we expended to do it" there's not a lot that springs to mind that would make going to Mars an economic proposition.
We got to the moon 50 years ago and still haven’t been back. It’s expensive to send humans into space.
Let’s get those Tesla robots to Mars… and Titan