I would suggest buying Canadian nightcrawlers. Some red worms are toxic to garter snakes. Canadian nightcrawlers are not. I just bought 500 very large Canadian crawlers, shipped to me for $54. I'm working on getting them wholesale from the source for $35, delivered to my door. Here's where I got mine Home - unclejerrysworms.com
He is a middle man and gets his mark-up. He gets the from DMF Bait Co.