I have a habit of cooking very large amounts and then freezing them. This definitely saves on work as well as stove time, making the dinner cheaper.
Spaghetti: I'll make a huge pot and then portion it for the freezer.
We eat spaghetti once a week, all I have to do is take a portion out of the freezer and put it in a pan.
It thaws out pretty quickly on the stove.
Then cook some pasta, and dinner is ready.
I do the same thing with soup. Make a huge pot, and you're good for a long time.
It really saves on time and money both.