Depending upon the wedding, it might be worthwhile to check into local colleges if they have a music program.   Sometimes they have students who work as DJs and would be willing to work on a wedding.

Be sure to check references and also meet the student. Sometimes college students can be shy or hesitant, which is not something you want from a DJ. You want them confident enough to manage the music and potentially what’s going on.   However, if you find the right person, this can be a big money saver.