Ace Hardware offers the Roundup 1-Gallon RTU Weed and Grass Killer Glyphosate for $18.99. That drops to $14.99 in-cart. Opt for in-store pickup to dodge the $11.06 shipping charge. That's the lowest price we could find by $15. It's rainproof in 10 minutes and includes a continuous spray wand. Deal ends April 30.