If you don't need the trunk space, I suggest you check out Yaris 1.5AT. Since you can get 09-11 even some 2012MY for your budget.

I used to have a Vios 1.5G AT and I'm getting somewhere in the league of 10-11km/l city driving with moderate traffic. The lighter hatchback Yaris, theoretically, should yield more. Atleast, IMO it looks more cooler than the Vios, rarer but the internals will be same as the Vios lang. So parts wouldn't be a problem.