My 150 gal cost me only $765 including everything except corals, fish and salt (which were all bargains too or gifts!) Everything was purchased used or it was free. The free items were given to me by other reefers getting out of the hobby.
I am a recent single mom on a budget. I no longer have the money I used to when I was married but I found a way to keep my hobby going on a tight budget.
$200 tank
$100 stand materials, DIY
$50 sanding/refinishing materials for acrylic tank
$0 lights (traded for something I had from a long time ago)
$60 bulbs 14000k 250 watt Phoenix x2, used but almost new
$70 rock, 70 lbs at $1 per lb and 70 lbs free
$50 Koralia 1400 x2 on sale + free gift certificate from frag swap
$15 Koralia 3 x2 used
$0 Heater, new Jager 300 watt
$0 Mag 750 return pump
$60 Octopus skimmer used
$40 SWC 160 skimmer used
$40 Sand purchased new
$0 75 gal sump found on the curb
$20 baffles for sump
$60 plumbing parts