With registered you have 2 different ways to market your cattle, if there good enough there registered if not there commercial. With commercial cattle there just commercial, but good commercial heifers will sale.
With registered there is a little paperwork involved, takes up very little time as long as you stay on top of things. If your not going to turn in data you really just have papered commercial cattle. Those numbers will mean alot to you, and the commercial folks buying your bulls. Pedigrees and names will also mean something, although the commercial folks may not know what name of this bull or that bull is, they have heard the different sires and recognize those names.
I did just what your talking about, slowly swaped the commercials out, still just a few for recips, have no regrets from doing it, I like trying to mate them and make the offspring better.
You can have 1 Registered cow with a bull calf, and sell that calf just fine, if you grow that bull out right. These animals will only be as good as your reputation over time.