An AoA is an array of arrays. But in fact your structure is more complicated, it is an array containing a reference to an array of arrays (so it is really an AoAoA). I can't be sure of what you intended to do, but I would guess that you really wanted this:

my @accounts = ( 
    [ current => 1000 ],
    [ savings => 2000 ],
    [ other   => 500  ],
);
[download]

instead of this:

my @accounts = [ 
    [ current => 1000 ],
    [ savings => 2000 ],
    [ other   => 500  ],
];
[download]

The difference, if you don't see it, is in the round surrounding parens, versus square surrounding brackets. The first one (an AoA) looks like this:

0  ARRAY(0x80359d38)
   0  ARRAY(0x80355ce8)
      0  'current'
      1  1000
   1  ARRAY(0x80359d50)
      0  'savings'
      1  2000
   2  ARRAY(0x803fe470)
      0  'other'
      1  500
[download]

and the second one is clearly more complicated, as it has one more level of nesting:

0  ARRAY(0x80359d38)
   0  ARRAY(0x80356108)
      0  ARRAY(0x80360410)
         0  'current'
         1  1000
      1  ARRAY(0x80359c18)
         0  'savings'
         1  2000
      2  ARRAY(0x80359bd0)
         0  'other'
         1  500
[download]

Ah, and yes, by all means, learn to use sprintf and printf, they are really useful as soon as you need to format output.