Nokia Lumia 1020 for BJD Photography?

There is a reason you can't find good examples, and it's because this phone's camera--while excellent in certain situations--is not well-suited to portraiture or doll photography. It's got a fixed focal length lens that is a very wide angle view (equivalent to the 18mm end of the T3's 18-55mm zoom). So all other issues aside, it's the wrong perspective for most people and people-like dolls shots (except for big group shots). You could use its close-focus capability for some artistic/novelty wide angle portraits, but you wouldn't want to limit yourself to this style.

I know the manufacturers give you a couple of seemingly meaningful data points to compare on (like megapixels), but the comparison of the 1020 to a DSLR is really apples to oranges. The 1020's camera may be best-in-class for a smartphone, but it does not have a DSLR's functionality or performance, it is more comparable to a fixed-focal-length lens point and shoot. It has a large sensor and lens by smartphone standards, but a very small lens and sensor by DSLR standards, so when you're reading the reviews, be mindful of what it's being compared to. Low-light performance is going to be poor when compared to any DSLR; "low-light capability" does not imply low-noise images, it only means the camera can jack the sensor gain up enough to focus in low light and says nothing about the quality of the resulting photo.

In short, it's nice to have such a decent camera on one's phone, but I wouldn't recommend the 1020--or any other smartphone--if photography is the main intended usage. The fact that you're asking about the T3 at all tells me you should be buying the camera, and not a new phone. If you're not already a brand loyalist, you should also be looking at Nikon's D3x00 line of DSLRs.

 

adam's advice is excellent.

Companies focus heavily on megapixels when they are marketing a camera towards consumers who are not familiar with the technical side of photography. Unless you're printing wall posters you won't need more than 12 megapixels. For most people, 12 megapixels is more than enough (a professional photographer would want more), but the companies like to make people think that more megapixels will drastically improve the quality of the photos.

The problem with a camera phone is they use what's called "digital zoom." Digital zoom is not real zoom. It does the same thing that cropping a photo does, so when you zoom in with digital zoom you are actually loosing megapixels. Optical zoom is real zoom. With optical zoom a photo taken zoomed out will have the same number of megapixels as a photo taken zoomed in.

One thing you want to keep in mind when deciding on a camera is if you only have x dollars to spend you don't want to spend it all on the camera. Lens, memory cards, camera bags, etc. all add up really fast. Especially if you are just starting out a mirrorless camera with interchangeable lens may be a better option than a DLSR. Mirrorless cameras are less expensive and that will leave you more money for lenses. The latest mirrorless cameras with interchangeable lens are really good quality cameras and comparable to entry level DSLRs.