I think you would never save enough water to actually save money. Urinals cost a few hundred bucks - the cheapest one I found with flush valve was $463 in a quick search. Water averages about $.02/gallon, and that urinal uses .125 GPF, saving about 1.075 gallons per flush. Ignoring installation and cleaning and maintenance costs, you would have to use the urinal instead of the toilet over 20,000 times to break even. From a resource consumption perspective it's an eternal loss as you've substituted fully recyclable water usage with a fired porcelain appliance with chromed brass and copper flush hardware. It just doesn't make sense, in my opinion, unless you really like having a urinal in your bathroom.
Edited to say: I was off by over an order of magnitude on the water cost. Average cost per gallon of water in the US is $.0015. That means you'd have to flush that poor urinal about 281,250 times to break even just considering the urinal cost, not the installation, maintenance, cleaning, etc. Never gonna happen. We're replacing urinals and flush valves long before they flush that many times in our commercial office building. The flush valves don't last that long, and urine salts build up in the urinal itself and can't practically be cleaned out so they end up replaced as well.