I have picked up several tanks out of the trash over the years, and
bought one that looked brand new at a garage sale for $1.00. All were
empty though. I refill them off my house tank, though they only get
about 1/2 full before the pressure equalizes. (The house tank has a
valve on it with a dip tube for liquid.) Besides the places like HD,
Lowes and some hardware stores that have the exchange system, and
regular propane dealers that refill tanks, around here some UHaul stores
refill the small tanks also. Larry