Kegs are guaranteed to hold pressure. The lids on these kegs are pin lock style, meaning they do not have a manual pressure relief valve.
This particular stock of kegs is purportedly in great shape!
4 Ball Lock Cornelius Kegs - $130!
Adventures in Homebrewing has some other great keg related deals...
Ball Lock Kegging Setup - $109
Used Ball Lock Cornelius Keg - $39
New 2.5 Gallon Ball Lock Kegs - $79
2 Keg, 2 Pressure Kegging System - $219
Related: Adventures in Homebrewing, Draft, Kegs, CO2 Hardware, Great Deals