You can tell the existing client that now the intro. offer has expired and for new pages, you will charge $x/Hour with limited revisions. If he really liked you

You can tell the existing client that now the intro. offer has expired and for new pages, you will charge $x/Hour with limited revisions. If he really liked your work, he would still pay. If not, you need to find a new client and this time, don't promise them unlimited revisions.