Quick verdict
If you're piecing together an industrial PC for SCADA or edge control, the Dell Embedded Box PC 5000 is a compact SFF system listed at $80 in used condition. The catch is spelled out in the title: there's no RAM and no hard drive included. For someone who already has compatible DDR4 memory and storage, this could be a straightforward way to get a small Dell platform for a control or gateway project.
Who it suits
This makes the most sense if you have spare components sitting around. The system supports DDR4 memory, so a few modules you already own may be enough to get it running. It also fits projects that need a small-footprint computer rather than a full tower. If you're experimenting with SCADA software, an edge gateway, or a local controller, this barebone is a candidate to build on.
What stands out from the listed details
The most obvious point is the price: $80 for a used Dell embedded box PC is hard to ignore. The listing describes it as an SFF form factor, which matches the space-saving intent of the Embedded Box PC line. The BIOS lock is noted as not enabled, which is useful if you want to install your own operating system without dealing with restrictions. Also, the memory type is listed as DDR4, so you know the motherboard generation before you commit.
Meaningful trade-offs
The main trade-off is that the $80 buys a barebone. Without RAM or a drive, you can't boot it until you add components. For someone without spare DDR4 modules, that could mean extra cost. The unit is also explicitly used, so it carries the usual risk of buying secondhand electronics.
Product notes
DELL EMBEDDED BOX PC 5000 w/ Intel Core i7-6820EQ 2.80 GHZ | No HD No RAM

The $80 listed price reflects a barebone starting point for a Dell embedded box build, and the supported DDR4 memory is a clear pointer to a usable platform. However, the system ships as a barebone, so you'll have to supply RAM and a drive before it can run, and the used condition means you should set aside expectations for pristine hardware.
Bottom line
The Dell Embedded Box PC 5000 is an interesting option for someone building a compact industrial PC for SCADA or edge control, provided you already have DDR4 memory and storage on hand. At $80, the base is affordable, but the total cost depends on the parts you add. If you're comfortable sourcing those components and buying a used unit, this is a practical path to a dedicated control machine.