Edited April 30, 2021
at 11:10 AM
Amazon has the 32oz Ortho WeedClear Lawn Weed Killer "Concentrate" for $7. Shipping is free with Prime or on orders $25+.
This recently expired Frontpage deal by oranges 32 for the Ortho "ready to spray" variation is also active again and on sale for 7 bucks at Amazon
Amazon.com : Ortho WeedClear Lawn Weed Killer Ready to Spray - Weed Killer for Lawns, Crabgrass Killer, Also Kills Chickweed, Dandelion, Clover & More, Fast Acting Weed Killer Spray, Kills to the Root, 32 oz. : Garden & Outdoor
I have 4000 sq feet of lawn. I prefer the Concentrate in a gallon sprayer for local application for my lawn because nearby trees sometimes grow roots near the lawn surface and sprout little leaves. I'm not sure if the "ready to spray with hose approach" might damage the trees. I think both variations are helpful depending on your situation.
Note: Lowes has the same pricing.
Spring is a great time of year, good luck with your lawns.