The Galaxy S20 series is quite expensive, with even the lowest-end model costing $1,000 in the United States. If you're not picky about cellular reception, the dual-SIM S20+ is just $800 on eBay, and now the dual-SIM S20 is down to $749.99.
This SM-G980F/DS model is a dual-SIM version intended for international markets. That means it has an Exynos 990 processor instead of a Snapdragon 865, which means it likely won't be compatible with 5G networks in the United States. It's also missing a handful of frequencies commonly used by US networks (like Band 29/30 on AT&T) and won't work at all on Verizon, Sprint, and other CDMA-based carriers.
Besides the connectivity differences, this is the same high-end S20 that typically costs $1K in the US. You get a large 6.2-inch 1440x3200 display with HDR10+ and 120Hz support, an under-screen fingerprint sensor, 8GB RAM, 128GB of storage (expandable via microSD), three rear cameras, Bluetooth 5.0, and a 4,000mAh battery.
Seller sobeonline1 has dropped the price on its dual-SIM Galaxy S20 stock even further. You can now pick one up for $700, an additional $50 off. Use the original link from above to grab one.