Restraint of trade - no-sell agreement?

My son wants to buy concrete polishing equipment from the manufacturer in his city. Wants to buy locally to get service, have recourse if there are defects, etc. The seller won't sell to any local buyer because he entered into an agreement with a former employee, who purchased the concrete-polishing service from the manufacturer. The agreement was that the manufacturer would not compete by offering such a service, and ALSO would not sell equipment to anyone else who would compete. I think the CNC is void, goes too far when it prevents third parties from competing; what do you think?