Upgrade to Luxman PD-441 turntable

Looking to upgrade the tonearm. Currently using an old Denon DA-307 arm with a Grado Gold cartridge (which I like for the $). This tonearm seems to transmit too much vinyl surface noise at higher volume settings (mostly noticeable in between tracks). I've already isolated the noise, I think, to the tonearm. Couple of people have mentioned a Rega 300 as a good option. Any other opinions? Looking to keep this upgrade in the $300 neighborhood.
the grado is solid, but the at150 cartridge, or garrott bros k2, or k3 will improve sound, lower the noise floor, and non will break the bank. the arm change is lateral.
I'm a bit suspect of the tonearm as some tech had changed out one of the pivot points that supports the arm to the tonearm base (it's different from the original) and the arm lifter seems to be shot once again. But your point is that going with a different tonearm in that price range would do little sonically. In that case, maybe I'll try to get the Denon arm fixed up properly, if that's possible.
Thanks for the guidance.
exactly..good luck