Step-father purchased a full setup (not including inhabitants) for $200 - just for the skimmer that came with it. I still have yet to purchase my own skimmer
He gave me the tank, stand, fuge. I've purchased all the lighting (MH
was $75 for ballast, bulb and reflector; VHO
was $150 for ballast, endcaps and bulbs; PC
was from the step-father for $0).
I've spent most of my money on water, salt and rock. Probably upwards of $2,500.
The tank wasn't the expense.