it was a 2ft cube with LR in it, cabinet and sump in it, not to mention all the power heads as well... i paid about $120 but prices then are very much different...
Why don't you just but a 12V adaptor (like those handphone charger or similar) then wire your LEDs in series to achieve 12V per circuit...
eg. 4 x 3V LED in series = 12V
Assuming each LED is 3 watt, then have 3 sets of this to get a total of 36W light set...
You should go to SIm Lim Tower! more DIY stuff over there... ask different shops for the price before committing... sometimes can be alot cheaper for the same item... good luck!