They are made better in general. Mainly is the wax potting process. Cheaper pickups are made essentially the same way, but the quality control can be a little all over the place. If there is a bad wax potted pickup it will be microphonic and be very noisy. Cheap pickups (at least in my experience) seem to be ceramic magnet as well. Which is not a bad thing, it's just a preference for most people. Ceramic magnets tend to be higher output than their alnico counter parts. Each different type of magnet gives you a different character. If you take one pickup... and replace the magnet and rotated different magnets in it, you will notice a difference in tone and output. Also, cheaper pickups tend to have a little less clarity and string definition. This is especially noticeable in cheap single coils. BUT! Sometimes you can get a set so cheap... if you wind up not caring for them... you can just dispose of them. But really, if you know what sort of tone you are after do a little research and ask around. There are a lot of youtube videos with sound comparisons. Most manufactures have very good descriptions of their pickups. Plus the Big 2 (DiMarzio and Seymour Duncan) have a money back guarantee. If you don't care for the pickups they'll take them back and send you something else. They want you to be happy.