With the recent announcement of the Note10, it was obvious the previous generation's price would drop substantially. And it just did, as the Note9 is now as low as $745 for the 128GB version, or $805 for the 512GB one. These are unlocked US versions, so you don't have to worry about carrier compatibility or warranty.
Considering the Note9 cost about $1,000 when it came out, this is a substantial markdown. Unfortunately, only the Lavender versions are this cheap, with the 128GB variant selling for $745, and the 512GB for $805. Considering the relatively small price gap between the two, the one with the most storage makes more sense.
If you're not into purple, the 128GB version costs $800 in black and blue, but I'd recommend going for the 512GB one if you want the latter, since it's only $20 more expensive. However, if you wanted the black Note9 with 512GB of internal storage, you're out of luck, as this particular version isn't discounted, and is still selling for $1,050.
The Note9 is still a very capable phone, with its 6.4" Super AMOLED display, S Pen, Snapdragon 845 processor, 8GB of RAM (on the 512GB model), 4,000mAh battery, dual rear cameras, and IP68 certification. If you want to know more about its differences with the Note10, check out our comparison post to find out more.