For years now, administrators at the community college here have been inundated with woeful tales from students unable to register for the courses they need. Classes they want for essential job training or to fulfill requirements to transfer to four-year universities fill up within hours. Hundreds of students resort to crying and begging to enroll in a class, lining up at the doors of instructors and academic counselors. Now, though, Santa Monica College is about to try something novel. This summer it will offer some courses for a higher price, so that students who are eager to get into a particular class can do so if they pay more.