We use the NextEngine scanner for smaller items.
There is a lot of work that goes into every scan and each takes a good bit of time.
I believe this is one area where it really is cheaper to rent.
I would also suggest that you try to learn as much as you can before making a purchase. At this point there are many 3d scanners. Some have great demos showing how smooth the surfaces are that they can capture. What they don’t tell you is that they CAN’T capture fine detail. Others capture fine detail but the base software package is very limited and you will need to spend thousands to be able to do anything with the model.
The scanners will often capture an image as well as a point cloud of dimensional data. The point cloud will contain many errors and will need to be converted for your intended use. Make sure you know what you want to do with the files. If you want to 3D print them, you will want to make sure that the surfaces are all closed and converted to something that your 3D printer can accept. Often an STL. If you intend to make changes to the object after scanning you may want it converted into a solid model.
Good luck with your project!