Is table really more importsnt than cartridge?

Thanks for the thoughtful responses thus far. If I may move the discussion from the theoretical to the practical -- I'm thinking of investing $300 to improve my analog setup and am wondering how to get most sonic improvement for the buck. My rig is a Thorens TD-320, with Shure V15VxMR cartridge, with a Gram Amp 2SE preamp. My initial thought was to sell the Cartridge for about $150 and use the $450 to buy a better cartridge. After reading posts about importance of the table itself, however, I'm wondering if it's smarter to sell the table for about $150 and use the $450 to buy a better table. Or maybe I can't buy any significant improvement for "only" $300? Any thoughts? Thanks, Rich

Thanks for the further thoughtful and helpful responses.

Newbee: Actually, I'm not sure what I'm looking for, since, for me, the present rig is as good an analog system as I've ever had. But as I read about equipment it seems clear that there's probably greater musical depth, detail, dynamism to be extracted from my lps than I'm getting now. Again, since I just got back into analog about a year ago, after 15 years away, and since I now own a better rig than I had back then, I'm curious to see how much more rewarding the vinyl experience can still be. Couple that curiosity with the new idea (to me) that the table itself is an important variable in sound reproduction and I began to wonder whether my table or my cartridge might be subject to greater improvement. My intuition, which the majority of the posters here and elsewhere argue convincingly against, was that once a table reached a basic level of steadiness and so long as it turned at the right speed that the cartridge was the key variable. I was also assuming that most so-called "mid-fi" vintage tables (Thorens, Dual) had already solved these table stability problems, so that there's was no need to upgrade my table (unless I wanted to enhance my turntable envy).

Sidssp suggests upgrading the table if and when I can invest about $800 into one. I'm wondering what table (with arm included) will provide me a clear sonic enhancement compared to my TD-320? Thanks.