One more thing, if you're gonna go the rebuilding route then best learn about battery safety, ohms law. Baditude here has some good blogs, I would link them but I'm on my phone. You'll also need to buy some supplies Kanthal, ohm checker etc so factor that into your budget.
Baditude's blogs is where I learned a lot, really good resources. And this Steam Engine | free vaping calculators keeps me vaping safe and worry free.