$20.00 for a bag of Preen? What, are you getting ripped-off because you're buying homeowner-friendly 10 pound bags from some stupid box store like HD or Lowes? Another example: "Ortho Total Vegetation Killer"... Dude! You're up in the middle of Amish country, right? (the answer is "yes", because I know precicely where New Philadelphia is! ) Well, SOMEWHERE up there, there's got to be a Deere/Lesco, or an Ag co-op facility like Southern States? Do you use any of these these guys locally? http://southernstates.findlocation.com/results.aspx As far as your question is concerned...I think you'll find you'll get a better "bang for your buck" when you begin buying wholesale. Deere/Lesco carries a nice landscaper-friendly granular formulation of Pre-M (pendimethilin) that generally runs something like around $20-$25 maybe $30, for a 50 pound bag! But like Greenie said, though, IF you're doing it 'for hire', you or no one else has any business applying any of this stuff unless he/she has a pesticide license! It'll makes absolutely no difference to the given OH pesticide agent whether your pesticides were later found to be purchased at a wholesale co-op like Southern States, or Home Depot. You'll be treated the same, regardless! So take advantage of this 'down' time....while it's still here! GET YOUR LICENSE!