Since "buy sprouts online" can mean a few different things, here are a few ways to use that phrase depending on what you're looking for.
If you want to buy groceries from and have them delivered to your door: buy sprouts online
Sites like Sproutman or GotSprouts specialize in shipping fresh, living sprouts. Since "buy sprouts online" can mean a few
What is the fee for delivery? | Sprouts Farmers Market buy sprouts online