850$ for...
- (outdated) integrated graphics
- old operating system
- hard drive instead of SSD
- large tower case
...is a terrible deal. there are far better options in the mac and pc world.
Oh please; It has a 1GB "video card". Either it is running HD4400 with 1GB RAM or the HD4400 is disabled because it really has a dGPU. In either case it offers better video than a mini. Haswell i5 and HD4400 are both current.
Old operating system? W7 is still preferred by many users.
Hard drive instead of SSD? An easily replaceable, 7200 RPM HD is better than the mini's standard drive.
From the description the Dell looks to be a reasonably-priced, expandable machine.