Go for a new soya cow machine,
Firstly i suggest u to go for new soya cow machine, as u can get loan n subsity for that, second its not easy to export a food product, specialy tofu becos its preservation 4 long time is very difficult n costly, you can earn gud only in local market.
For exporting a food product u need to meet very strict quality controls n product testing, it will cost u more then your soya cow machine, so first purchase the machine, then think abt other things
Where are you frm, and wt u wish to do ??