marakanetz is right on the money, that is, don't spend any on the turntable, but money spent on a cartridge is not wasted. One word of caution though, what will work well on one turntable (such as a modern one of good mass, with an arm of good mass) might not work all that well on something like what you have. But it is fun to find out. I have found that some of the old turntables actually work surprisingly well compared to some of the cheaper, high end turntables available today. I'm not saying that you shouldn't upgrade your 'table, I think you should, but it shouldn't stop you from getting a better cartridge.
I would set my aspirations to a cartridge that seems appealing to you, and one that would seem to work well on a table that seems appealing to you. What is there to lose? So long as you are willing to accept a table upgrade in the future, willing to accept that your present table may have limitations, the only chance you would really be taking is that your present turntable might or might not sound good, while you look for a turntable that you really want. Judging from the rest of your system, a better table is emminent. You could be looking for both a better table and a better cartridge.
