+1. This is what happens with most people out there. There many good used phones too, but finding them is not very easy for "everyone".
Now prices are also very lower for budget phones and there are lots of great options in new officially released phones too, so there is usually no need to spend money on used risky flagships, as their repairing costs are fairly sky high too.
Qmobile or Infinix may have lower quality, but their repairing costs are very economical too. That's the benefit in them.
Previous Z9 or Z8 were not that impressive in performance, but Z10 is very good and extremely reasonably priced for what it offers. However, 3GB RAM and very powerful processor helps mostly in gaming only. Everyday usage tasks don't need that much power.
Use Opera Max to save data bandwidth. It can also restrict data usage of your restricted apps. Also lookup "settings" on data consuming apps and make sure that they don't use mobile data unnecessarily for syncing etc.
Edit: Enable data saver settings in chrome and also use Opera Mini, UC mini, or UC Browser. They save a lot of data.
