The Samsung Galaxy S9 comes in slightly different variants, depending on which part of the world it was intended to be sold in. Whereas the version designed for the US market comes with a Qualcomm Snapdragon 845 chip inside, Galaxy S9 devices sold internationally all feature Samsung's Exynos 9810 chips instead. Many consider the Exynos devices superior due to their edge in performance (and better development), but others prefer them because they're the only version that can be purchased with dual-SIM support.
If you fall into either group (or both), you can find the dual-SIM Samsung Galaxy S9 (SM-G960F/DS) on eBay right now for just $659.99. Samsung doesn't sell the dual-SIM S9 in the United States, but the unlocked American version of the phone (SM-G960U) is currently going for $719.99, making this deal a $60 saving for an arguably better device. Previously, the best deal we had spotted had been for $674.99.
Aside from the differences in chipsets and LTE band support, all Galaxy S9s are the same. They feature a 5.8" 1440p AMOLED display, 4GB of RAM, 64GB of onboard storage (with microSD support), a 12MP main camera, an 8MP front-facing camera, and a 3,000mAh battery. The Galaxy S9 also has an IP68 water-resistance rating and supports wireless charging.