With orders of $25 or more, Amazon offers Prime members the Fred and Friends Mr. Tea Silicone Tea Infuser for $2.79 with free shipping. (Non-members can spend $49 or more to qualify for free shipping.) That's at least $5 less than you'd spend at a local retail store. It's made of BPA-free silicone and is microwave- and dishwasher-safe.

Note that this item is part of Amazon's "Add-on program" and can only be purchased with an order of $25 or more.