Wise advice from Swampwalker. Using an LOMC+SUT well is not simple, using them badly is.
Also agree with Stanwal's advice to upgrade your cartridge last. Table, arm and phono stage must be good or you just won't hear what a costly LOMC can offer. As he also noted, a cartridge has a limited life span. It isn't prudent to upgrade if the rest of your front end won't reach an appropriate level before it wears out. Tables, arms and phono stages are forever, so they're a sounder investment.
Further, an entry level cartridge can sound amazing with a good table, arm and phono stage.
Extreme example: I'm currently demoing a $125 MM, temporarily setting aside my $8K (retail) LOMC. My table, arm and phono stage retail for ~$19,000, a rather silly 152 times more than this MM cartridge.
How does it sound? Damned impressive, quite the equal of any $1,500 LOMC that I've heard.
OTOH, when I play my fancy LOMC with lesser TT's, tonearms or phono stages the best I can hope for is that it'll sound pretty good, which isn't much for the price. Sometimes it sounds boring. Most often it reveals the weaker component's flaws and the net result is unsatisfactory. Now when everything's right the LOMC is utterly glorious, light years beyond the $125 MM. But everything else must be right - first.
