Often printers charge a set-up fee, so you will need to print off a few to be cost-effective. If planning a very large print run, you will need to make sure that you are able to inspect a series of proof prints to correct any problems before the edition is printed. Make sure you are firm about resolving any issues at this point.
Some artists keep a record of print sales so that damaged prints can be re-issued, but apart from that, it would be highly unethical to reproduce images once a limited edition is completed. With traditional print media, the printing plates are destroyed, often with a copy of the defaced plate printed off as proof of this. If you are not limiting the edition, you can just print as many as you expect will sell. Edition sizes on artist's original prints, such as lithographs and etchings, are in part limited by the durability of the printing surface and the effort involved in printing them, but these factors are not relevant in digital printing.

