After 35 years of smoking, and not having health insurance, my Symbicort inhaler costs me $275/month. My Spiriva HandiHaler costs me $185. My albuterol inhaler is the cheap one, only $35. These are my monthly expenses for medication. I'm sure your doctor has given you the lecture, but for many people who smoke, if you're not on these meds yet, you will be.
You don't mention how much you and your husband smoke, but if it's a pack/day each, you're only spending about $115/month. I don't know that an e-cig can beat that. But, even if you were to buy a good kit, which often has two complete e-cigs in it, every month, by the time you add juice to it, it would probably be somewhere in the vicinity of $125-150. If you learned to make your own juice, you could probably shave about $50 off that, but there's a learning curve there, too, that will cost a little more initially because of the amount that doesn't quite make the cut.
I wish there had been e-cigs around a long time ago or that I had discovered them earlier. You may not save money, especially initially, but there are so many intangibles that you can't put a monetary price tag on that make it worth it (and you may save $25/month in Febreeze alone).