If price is your motive, stay away from non-refillable Pods.
3 Halo pods are about the same cost as 2-3 months e-liquid to me.
Therefore I don't like Pods or Halo. I consider it all a rip-off to be honest.
It is possible to vape for very low cost if you want to. I have spent under $50 this year.
$12 on a few spare coils, $8 on wire/cotton, $26 on e-liquid DIY supplies, $1.40 on syringes. That's since November 2017 actually.