For Amazon's Deal of the Day today, you can get Samsung's Galaxy S10 series for up to $300 off of its normal price, a sizable discount. Specifically, the max discount applies to the Galaxy S10+.
You've got some options here. The base model with 128GB of storage is $549.99 instead of $849.99, but the same discount applies to the 512GB model, which you can grab for $799.99. If you're a Verizon customer though, Amazon sells a bundle that comes with a Verizon eGift card. Note that the eGift card is only worth anything if you activate the unlocked phone on Verizon, but it can be worth up to $450. The bundles with the Verizon eGift card only cost a few dollars more.
The Galaxy S10 is also on sale, although it only has a discount of $150. That means that the 128GB model is $599.99, so it actually costs $50 more than the S10+. The S10 Lite has the same $150 discount, so you can grab it for $499.99. And like the S10+, both the S10 and S10 Lite are available as a bundle with Verizon eGift cards for a few dollars more.
If you want to check out the deal on Amazon, you can find it here.