Here's where the numbers get interesting. A disposable might cost you $10 to $15, and it'll last maybe a few days to a week, depending on how often you vape. That adds up fast.

A pod kit, like the VERTEX-15K or the LINQ-SLIM, costs more upfront—maybe $20 to $40 for the device. But then you're buying e-liquid, which is much cheaper per milliliter. A bottle of e-liquid might cost $15 to $20 and last you a week or more, depending on your usage. Over a month, you're likely saving money with a pod kit.

Of course, there's the initial investment. If you're not sure you'll stick with vaping, a disposable might be the safer bet. But if you know you'll keep at it, a pod kit pays for itself pretty quickly.