Home Depot offers the Pure Garden Glow-in-the-Dark Pebbles 100-Pack in Green, model no. 82-3401, for $6.72. (Amazon has it for the same price.) Opt for in-store pickup to dodge the $5.99 shipping fee. That's tied with last week's mention and the lowest price we could find by $3. These pebbles absorb energy from the sun during the day to light a pathway at night.