As has been stated above, everything is important.
It then, IMO, becomes a question of value for money. As a result of that, it becomes a question of where you focus your money.
Once again, IMO of course, it then goes this way.
Good turntables are not cheap (even used). Good phono stages are not cheap, particularly for LOMC (even used).
Good tonearms can be had at a more reasonable cost (new or used).
Good cartridges can be had at a more reasonable cost (new-I wouldn't consider buying a used cartridge personally, but to each his own, although I do think a "tweaked" cartridge is the way to go).
Therefore, IMO once again, strictly on a cost basis, the following formula should apply:
Tied for first (within reason): Turntable and Phono Stage
Second: Tonearm
Third: Cartridge
It then, IMO, becomes a question of value for money. As a result of that, it becomes a question of where you focus your money.
Once again, IMO of course, it then goes this way.
Good turntables are not cheap (even used). Good phono stages are not cheap, particularly for LOMC (even used).
Good tonearms can be had at a more reasonable cost (new or used).
Good cartridges can be had at a more reasonable cost (new-I wouldn't consider buying a used cartridge personally, but to each his own, although I do think a "tweaked" cartridge is the way to go).
Therefore, IMO once again, strictly on a cost basis, the following formula should apply:
Tied for first (within reason): Turntable and Phono Stage
Second: Tonearm
Third: Cartridge