Its gotta be close to 400 for the standard edition. Tho there will most likely be a cheaper and expensive versions like the current Switch with Lite and Oled.
My prediction would be similar power to the Series S. Would like more Ram but less Tflops. $400 for the LCD with 64gb of storage, and above 400 for the Oled with 128gb. The problem would be the different prices in different regions. Since Japan is a key market for Nintendo, I wonder how they would tackle this on-going weak yen situation. If its priced at $400, that would make it closer to 60,000 yen in Japan. Nearly PS5 level prices. However, this shouldn't be that much of an issue if the current Switch gets a price cut.