How much does it cost to patent software?
I do not think you can ‘patent’ software. You can ‘patent’ an idea or implementation used in software. The cost to get a patent varies highly from $500 to upward of a $1,000,000. It depends on the scope you want the patent to apply to (worldwide, nationally etc.), the duration of the patent. And mostly the complexity of the patent. This is because you need to prove the ‘idea’ or ‘implementation’ is orginal, not in the public domain, and different to any existing patents. If you just want copyright on software then that is FREE and automatic upon proper software licencing.
