help finding true comps to get accurate price

[Mike Ross]

any advice on how to find comps besides zillow trulia etc .  

 i have a house im trying to get under contract the sites say 150k average the seller says its worth 290k but wants no less than 200k i know he bluffing ......but he called me from a mail i sent a month ago .... how can i get a correct price point on comps .... its a pretty house 5bdrm 4 bth around 1600 sqft which is small i know but he also owes 5k in back taxes...... thanks guys any help or point me in the right direction would be of great service