You may have to spend money to replace the battery, but you have saved money on the "conventional" components of a Toyota/Lexus hybrid vehicle. Brakes on a hybrid vehicle do not wear as fast so require less service. There is also less wear on the internal combustion engine, so you will save money there also.

Of course, if you are concerned about owning a hybrid vehicle, lease one. I have been leasing Toyotas for a number of years now and have had no problems. It probably helps that I am an "average" consumer:

I just want a vehicle that I can drive for 4 years.

I do not modify my vehicles.

I do not drive more than the allowed distance per year.

I do not find the restrictions in the lease agreement prohibitive (may include not driving into the USA). Check the fine print.

I service it at the same dealership where I leased the vehicle.

I am a long-term, repeat customer at that dealership -- we have established a good working relationship. Because of this, they are more lenient with me regarding wear and tear on the lease return.

I am seriously considering a hybrid vehicle for my next car. I would have no hesitation leasing a Toyota or Lexus hybrid.