The Lumia 830 is designed to be an "affordable flagship" device. It features a 5-inch display at 1280 x 720, a 1.2 GHz quad-core processor, and 1GB of RAM. It has 16GB of internal storage, expandable with a microSD card. It has a 10-megapixel rear camera, along with swappable back shells. In Brazil, it will retail for R$1,199, or about $530 US.
The Lumia 730 and 735 will be available a few weeks after the launch of the 830. The phones have nearly-identical specifications, with the 735 being a single-SIM, LTE capable variant of the 730. Both devices feature a 4.7-inch 1280 x 720 display, 1.2GHz quad-core processor, and 8GB internal storage, which can be expanded with a microSD card. They have 6.7-megapixel rear cameras, while also having 5-megapixel front-facing cameras. The Lumia 730 will cost R$699, while the 735 will go for R$899, $290 and $380 US, respectively.
Thanks to Zapella for the tip!