While I am sure you guys mean well, there is a marked difference between "pounds" and "gallons" of propane. A 100 gallon tank of propane would hold 422 pounds of propane.
Eye, if all else fails give these folks a call:
C & R Recyclers
19242 State Route 576
Pioneer, OH 43554-9797
They are in extreme NW corner of Ohio by Indiana,Michigan line. I bought a certified,reconditioned 250 gallon tank for $250.Repainted,looks like brand new. That is what they specialize in,is propane tanks. They have smaller as well.Sizes and prices vary,but great people to do business with.