Before I really answered the question, I'd want to know: what do you want to shoot a handgun for? If you're preparing to use it for carry or home defense, do you envision using a red dot in these circumstances? If not (and I would recommend not), then start of with the gun configured the way you intend to (potentially) use it. If you're preparing for competition, is it a type of competition in which you'll use a red dot? (Learning to shoot on a USPSA open-class gun = not a very good idea).
The only circumstance in which I'd really think it a good idea would be if you were planning to become a handgun hunter, or maybe steel competition. But even in those situations, learning to use sights is not that hard; I mean, virtually everyone who's ever learned to shoot a handgun has learned on them. I like having a red dot on one of my guns, and would consider getting them on more; but when I take my son shooting, I'll hand him the open sighted .38 instead of the red-dot mounted .22, and gladly pay the difference in ammo to have him learn to shoot a gun the way they're shot the vast majority of the time, and the way he'd most likely need to shoot one if he ever did, god forbid..