The price of a Paloma tankless water heater is between $700 and $1,200, as of 2015. Prices vary between indoor and outdoor models. Prices also vary between residential and commercial units.
DesignerPlumbing.com sells outdoor water heaters for $700 and $900. Indoor models cost between $800 and $1,000. Prices include ground shipping costs.
PalomaStore.com sells residential water heaters for $759 and commercial units for $899. They also have tankless combination water heaters for residential and commercial use that cost between $800 and $1200. Prices also include shipping costs.
Occasionally, eBay has used Paloma water heater auctions for about half the price of new units, not including shipping costs.