In Berkeley weather, might I suggest stuffing your pants in a plastic bag in a backpack and wearing shorts for the duration of the ride? Maybe stepping up to light jogging tights/pants/leg warmers in the depths of January/February cold? Unless you’re riding in the dead of night, 5 miles to the gym in NorCal conditions shouldn’t require any bank-breaking top-of-the-line REI gear designed for a 3-week bike packing trip in the Cascades.