Over the past 1.5 years, my quarantine tank turned to a rescue-coral tank to my only tank...so I decided it needed its own profile. This tank has beaten all odds...and was done on the cheap.
10g drilled tank: $5
10g sump (used acrylic baffles): $10 (including the acrylic and silicone)
Mini 404 pump: Free at frag swap (is used as a return pump)
Plumbing: $10
HOB filter: $5 (on clearance...used as a carbon/phosphate reactor)
Sand: Free
Live Rock: Free with purchase at a LFS
Metal Stand: $5 (I think...the previous owner might be able to correct me)
Koralia 3: I had a gift certificate...so I think I only paid a couple of bucks
Tunze 9002 skimmer: $135 purchased for the 40g, but moved it over a couple days ago
2x70W MH: $75 for both plus $20 eBay bulbs
Controllable Heater: Had a gift certificate
Flood Lamp: $15
Mag-Float: $5
Auto-topoff system: Free...won in a raffle
So, for a little over $250, I have a pretty awesome "QT-Rescue-All in One Tank