You've never used Android 4.3 on 512 MB of RAM, right? I have and it is unusable. The base OS and the base apps, like the stock Android browser do run, but nothing is left for other apps. A minimum of 1024MB is needed.
Also that phone is $100 in the US. To get the price in EU or most other markets multiply with an amount between 1.5 and 2
An android phone without 'Google Apps' does not offer much more than FxOS in my opinion. I test drove an AOSP build of android for some time, without Google Play and other 'non-free' Google apps, and there's not much you can do.
Very few application vendors provide .apk's to install outside of Google Play and they don't provide them from other markets available internationally. f-droid has some applications but not a huge amount.
Basic functionality like Facebook, Twitter, 'sharing' photo's to social media,etc don't work if you can't install those apps.
What I ended up doing was installing Firefox (Mozilla provides apk's and it's available from f-droid) and using web apps.
Firefox OS on the other hand provides all this functionality out of the box.
Also that phone is $100 in the US. To get the price in EU or most other markets multiply with an amount between 1.5 and 2