Cartridge for a Pioneer PL 630?

Nagaoka MP110.

Fidelity-Research FR-5E or Stanton 881 mkII Stereohedron 

But they are not less than $200. A lot more and not available anymore except on eBay. The Nag is solid and cheap.

@noromance ebay is not the best price guide, fellow audiogonners are better, sold a few fr-5e for $150 and fr-6se for under $200

You can get a new Shure M97XE or a Grado black for under 100 bucks. Both of these would be a nice fit for the Pioneer!

+ 1 for Yogiboy , the Nagoka MP 110 is a bit better though, and very well made .

There are many cartridges that "can fit", but what about the sound quality?

Maybe you can find Astatic FM100 or MF200 or Glanz MF31L in $200-300 category, none of the entry level Grado can compete with them. And the Moving Flux generator is unique (not the regular MM or MI). The Grado kicks ass when it comes to the top models like the signature XTZ by Joe Grado (my favorite). I have a few Grado branded "DJ200i" - they are actually a Grado Black, vintage Fidelity-Research FR-5E kills them. 

The Audio-Technica AT120e is also good entry level cart and better than Grado entry level carts. The old Stanton 881 (and higher) and Pickering 3000 (and higher) with Nude Stereohedron styli are really good cartridges!