It depends on gas or electric. Also, like most folks I’m a flat rate guy so my price includes COGS. For residential I do 40/50 gallons, mid-highs (size/height) for about $900. Those of course are the 6-year warranty ones. But don’t buy anything over 6 years because it’s a waste of money.
However, if somebody provided the water heater I’d have it done for say $300.