Any amount would do,  as long as you can handle or manage the things that might happen like those risk that you may lose what you have invested. Small amount of investment is not a big deal,  all you have to do is to make sure that you would be able to make a profit out of it,  big things comes from small beginnings as they say. So that mind the figures,  just do what you have to do in order to make it a successful investment.