Simple, common, and public items have a Device Rating of 1 (Appliances, public transit, etc).
Average items have a DR of 2 (Guns, cyberware, vehicles, drones, etc)
Security and corporate items, plus Alphaware have a DR of 3.
Military, Betaware and other high end devices have a DR of 4.
Cutting edge devices like credsticks, deltaware and black ops vehicles have a DR of 5.
Really top end stuff has a DR of 6.
This is just the default rating though. It can be beefed up by linking it through your commlink and PAN. A Transys Avalon is a DR6 and only costs 5,000¥.
Bull