No. Where I work, its ONLY-BUY-OUR-DEVICES rule.
I work for a large global handset manufacturer (hint: largest in the world). Every morning and every evening I pass through big metal detectors and stand in a queue to get frisked everytime. As per policy, I can only buy devices made by my company if I intend to use it in office. If I buy something else, the security guards at entrance are happy to pack my device in a one-time sealable, semi-transparent bag, which ofcourse has to be in the same condition when I leave office.
In case you are wondering... NO, I dont get discounts for buying any mobiles.