If you can get those plastic barrels for $15, I am amazed.  The last ones I saw for sale here were close to $200.  Luckily, I beachcombed one, and was given another by a friend who no longer needed it.  I find them perfect for melting snow in prior to mixing up nutes, and/or just supplying straight water to a water only grow.  If I got them for $15, I likely have three or four of them.   
