Yeah that's the problem.
There's the xperia x compact already available and then there's this.
X Compact is around $350-400 while A3 2017 will be around $300 and probably not available in many countries including usa.
I'm still using my 4.3" Moto E and a 4" Lumia 532.
X Compact Sony did not launch in my country so this is the only phone to look forward to. $300 is bit much for the specs but it's not like there's any other options.