Such a scheme would never be done with Titans (for one thing, they're retired, for another, it's not necessary to go all the way to orbit, and it's a very expensive vehicle). It would be done with suborbital reusable vehicles, like the ones currently being developed for space tourism. Their cost per flight, and cost per pound to the upper atmosphere, would be lower by orders of magnitude. It would actually provide a great market for them.
The differential in cost of Orbital vs. Sub-orbital is irrelevant. The cost of building and launching even the cheapest of space vehichles is prohibitve at best, and insane, at worst.
You seem unable to grasp the fact that it will take hundreds-of-thousands of launches spanning untold centuries.
Puh-leeze!
Do the Math!
You are joking, aren’t you?