If you really mean it must be under $50, your options are very, very limited. Of the ones I know of that enjoy a decent reputation, there is the Audio Technica 95E, the Ortofon Omega, and the Red Ed elliptical. Never heard any except the AT, which is nice for the money, but unless your current cartridge is warn or damaged or really crappy, personally would save my pennies for an Ortofon Red at $99, which I do have one of and think is truly excellent for the money.
How is the Ortofon Red against the Shure m97xe? I was weighing options to optimize my setup and buying an "audiophile" turntable seems ridiculous. The cartridge, preamp and speakers are my only real options, as the pioneer receiver is wonderful.