Three things separate a $170 table from a $1,300 one — and sellers use the words loosely, so here's the plain version:
14 ga heaviest · 16 ga standard commercial · 18 ga light-duty. Counter-intuitive: a lower number means thicker steel and more dent resistance. Heavy daily prep wants 16 (or 14); light/occasional use is fine on 18.
304 (a.k.a. "18/8") resists rust and food acids and is non-magnetic — the standard for wet, salty kitchens. 430 is cheaper and magnetic but rusts sooner where moisture sits. For a dishroom or wet line, choose 304.
A stainless base won't rust anywhere; a galvanized (zinc-coated steel) base is cheaper and fine away from standing water, but corrodes near floor drains and wet zones. The top is usually stainless either way — the base is where brands cut cost.
Rule of thumb: busy wet line → 16 ga / 304 / stainless base. Dry storage or light use → save with 18 ga / 430 / galvanized base.