Amazon offers Prime members the PetSafe Healthy Pet Water Station for $9.63 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $7.31.) That's the lowest total price we could find by $5. It features automatic water distribution and 1-gallon capacity.
Note: It's not expected to ship for two to four weeks, however it can still be ordered now at the above price.