Ebay should be an acceptable source of used hardware, if you're going that route. Note that there are several manufacturers of PLC equipment (Allen-Bradley, Siemens, Bosch, etc).

PLC programming is evolving with AI-assisted coding, low-code platforms and IT-OT convergence. Industry experts from Emerson ...

STÄUBLI TEC-SYSTEMS is launching the uniVAL pi software that will allow robot programming to be implemented via the PLC, using Plug & Play in Siemens TIA Portal. Thanks to this optionally available ...