I assume you mean the cheapest that will run ArchiCAD? If so, then you can get pretty much anything.
Running ArchiCAD well is a different story though. Your local sonystyle is probably the best bet to find what options you have available.
Josh Osborne - Central Innovation
HP Zbook Studio G4 - Windows 10 Pro, Intel i7 7820HQ, 32Gb RAM, Quadro M1200