I have the Atlas 3D scanner, and you can read about my failures and successes in Atlas 3D forum here.
Most "inexpensive" (< $2000) scanners are either laser scanners or sense scanners (depth sensors).
Depth sensors like Sense 3D, iSense, Scanify, RealSense or the Microsoft Kinect are designed to capture a large area at one time, have a minimal focal range from about 2-3 ft, and usually produce scans that lack small details. They rely on capturing the color image as a texture, but the actual model underneath is usually pretty low quality.
If you're looking to scan objects for printing purposes, the meshes these scanners create are pretty rudimentary.
For scanning objects with good detail, a turntable laser scanner is a good solution. However it has its own drawbacks as well. First and foremost, laser scanners are affected by light and reflections. These 2 things are probably responsible for 60% of all scanning errors and noise.
Secondly scanning irregular objects present challenges of it's own. While scanning a simple, mostly flat object is not a problem, scanning objects that cave protrusions or concave areas and holes is a problem, because the laser can always "see" inside these areas while the protrusions create blind spots.
Some (high end) scanners work around these problems by either using a articulated turntable that can rotate the object at multiple angles, or the scanner has multiple lasers and cameras. A good example of such as scanner is the NextEngine. It uses multiple lasers sources and multiple cameras. They also offer a special turn table that can automatically tilt the model while rotating it. Another nice feature of that scanner is that it integrates with SolidWorks toproduce solid models, rather than simple meshes.
But I digress. The NextEngine is NOT inexpensive, and although at $3K for the base model, it's out of the price range for most hobbyists, it's still one of the best bang for the buck scanners on the market
For me, The Atlas 3D offered the least expensive means to dabble int the scanning hobby, and quite a few hours of entertainment and educational fun. I "forced" me to learn how to use some programs I had previously only glossed over, like MeshMixer and MeshLab.
Last but not least, you might also want to look at "structured Light" scanners. I never worked with one, but the theory behind them is that they shine a light pattern (usually stripes) onto a 3D object, then a camera takes multiple still from various angles around the object. The distorted stripes that wrap around the model are then processed by the software to interpolate the 3d model.
BTW, sense cameras are a form of structured light scanners, although they use some type of infrared projection to project dots on an object ("a thousand points of light").
Anyway, I hope this helps.
To print or, 3D print, that is the question...
SD3 printer w/too many mods, Printrbot Simple Maker Ed., FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.
