Ultimately, choosing between the two comes down to what you want from a phone. The Note 9 is still a great option in 2019, but if you're looking for the absolute best, the Note 10+ is the obvious pick.
The Note 10+ would cost 15000-20000/- more than the Note 9, but the sheer number of new features justify the price.
The Note 10+ has a much more premium design with a gradient pattern at the back and an edge-to-edge screen, and you get double the amount of memory and internal storage.
You also get an S Pen with more features, a larger 4300mAh battery, and 45W wired charging as well as 15W wireless charging and the ability to wirelessly charge other devices. There's also an ultrasonic fingerprint sensor, Wi-Fi ax, Samsung Pay, and IP68 dust and water resistance.
The Note 10+ also has four cameras at the back and a 10MP shooter up front, with Live Focus for video and Night Mode coming to the front lens. The sheer number of features make the Note 10+ an obvious choice for an upgrade, but it is annoying that there's no headphone jack anymore.
If you're already using the Note 9, Samsung is hopefully should be offering a trade-in promotion wherein you'll get up to 30-40k when upgrading to the Note 10+. Given that a new Note 9 is going for 50k, it's a fantastic offer that lets you easily upgrade to Samsung's latest flagship.
