Get ready to save some serious cash next month.
Credit: Photo courtesy of eBay.

Coffee lovers were outraged when Starbucks launched a reusable cup promotion last month that ended up selling out in just a few minutes—but a new promotion tied to Starbucks' latest reusable tumbler might make up for the snafu, especially if you're able to get your hands on one.

Starbucks is now selling a new 16-ounce tumbler (officially called the Brewed Refill Tumbler) that you can use to get a free Grande hot coffee or tea every single day in January. Delish reports that if you simply hand the barista your reusable tumbler, they'll fill it with any of Starbucks' brewed coffee or tea—from Blonde Roast to Mint Majesty.

This tumbler is a tad more expensive than Starbucks' other reusable drinkware—it's available for $40 plus tax.

But if you break down the math, it could save you quite a lot in January if you drink coffee every single day: brewed coffee at Starbucks can cost anywhere in between $2.39 and $2.89 plus tax, with prices varying in different markets. There are 31 days in January, so you'd be looking at upwards of $90 for a month's worth of Grande coffees in most metropolitan areas. With the reusable tumbler, you'd save around $50.

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Even if you don't drink coffee every single day, Delish points out that using the tumbler for 14 free coffees will allow you to break even—and get a trusty new coffee cup. Plus, just think of all the paper cups you'd be saving all year long.

Starbucks’ reusable mug would make a great gift for any coffee lover in your life, too. If you can't make it to Starbucks, or if you find that your local store has already sold out (darn!), you can find a few floating around on eBay. Look for a stainless silver design featuring Starbucks' signature logo towards the bottom of the bottle.