Initially designed to bring the fun of robot arms into the hands of everyone, the MeArm is a robot arm you can build for less than $50, using 4 servo motors, some screws and acryllic. The acryllic isn't entirely necessary too, you can 3D print or CNC mill your arm housing!
It began as a small project uploaded to Hackaday back in 2014, winning the Hackaday award in 2015 and then went on kickstarter to fund its own independant control board. Now version 1.0 is available as a complete kit in the UK. The build it yourself version uses a Raspberry Pi or Arduino for control and is extremely simple to make yourself, the designs are all open source and you can grab a PDF of the stencil for the frame here.
As you can see the MeArm is exactly as you'd expect and for such an inexpensive little project, it's worth a shot!
Pickup some servo's here.
3D print the housing with STLs from here.
Screws for assembly can be found here.