Udemy offers PMP courses that can count towards the required contact hours for PMP certification. They have more of an a la carte services, with bite-sized, open-source courses. Anyone can take them because they're open source, but, of course, you aren't getting official PMP certification, just preparing. Courses are priced individually and average $10 to $25 each. Of course, that can add up, and you'd need to be organized and log your hours. Another thing you may want to consider is that Udemy currently holds an F rating with the Better Business Bureau, so I can't fully recommend even the Top Udemy PMP Courses.