Low oil pressure does not warrant a rebuild unless new rings and higher compression is the priority, assuming it has good compression, low blow-by, and doesn't smoke or use oil.

Drop the pan and replace the oil pump, rod bearings, main bearings, and pick-up screen. May as well do the rear main seal while the rear main cap is off.

If the screen had plastic bits in it then pull the timing cover while the pan is off and put a timing chain and gear in it.

$300-$400 total.