So far I am loving my Rega P-1. I just got 180G vinyl of Dark Side of the Moon and Dave Masons first solo album and they sound great. However I was wondering if someone could answer these questiins

-How long should a cartridge and stylus last with moderate play?

-Where can I go to get a stylus brush and LP cleaning (online)

-As you upgrade in cartridges what is the primary improvements (i.e. sound?