Here is my run at a $900 build. There are some compromises in this build to get onto the Intel Skylake platform. The storage is on the small end (only a 250GB SSD), no optical drive, and no aftermarket cooler. My reason for the Skylake platform is has a good upgrade path and a long life for the system, 4 years plus. This system can easily have more RAM added, more storage added, or an after market CPU cooler installed.
All of this of course is my opinion. However this is what I would do if it was my $900 to spend. Hope you like the build. Let me know what you think Anadroid614.