Understanding foreclosure and quit claim deeds

[Giovanni Luna]

I found a foreclosed home and  it says quit claim deed. I know I have to pay off the back taxes on it and closing costs  but say if the listing prices is 200,000 and taxes I would have to pay on back taxes is 10k and closing costs 10k ; would I have bought a 200k house for 20k and I own it or would it be 20k and I would still owe 180k on the mortgage?