over, more than

It is entirely correct to use over in place of more than:

• Jackie’s emerald ring cost over a thousand dollars.
• Because of traffic, Eric was over 30 minutes late.

In the 19th and early 20th centuries, some American newspaper editors banned the use of over to mean more than. Although the ban seems to have stemmed from editorial preference rather than any usage problem, some style guides still object to using over in this sense.

However, major dictionaries and style guides accept this usage. Interestingly, Fowler’s Modern English Usage (third edtion) says the use of over to mean “more than” has always been considered standard in Britain.