At some point, you run into diminishing returns as to how much car you can make out of "x" amount of raw material, with the R&D already paid for. The Maruti Alto was the example I gave, because it is far, far, faaar past that point... Another car that's possibly there is the Nissan Versa. The Jetta is a likely candidate (simply for the stripping it gets in Mexico to meet the price point it hits in the US).
Hey, the Nissan Tsuru (Sentra to you folks... B13 to any Niss-o-philes on the board) is still on sale in Mexico. That's a car whose R&D were paid off way back in 1996 when it was retired everywhere else. Far as I can tell, it's about $2k less than the Versa.
But:
And then consider it has less legroom than the Versa, poorer fuel economy and truly scary handling... that's pretty much as far down as you can go for a "normal" sized car.... actually, too far down... and it's still way too close to $10k for no discernible benefit over what's currently on offer near that price point. (Versa, Mirage - which also has more legroom... I used to drive a B13), etcetera)