We got ourselves a programmable keypad with multiple dials from Taobao for RMB 155 (USD 24). We found this one to have the highest cost-to-performance ratio among other alternatives.
Each dial has three actions : left turn, right turn, and click. The keys uses mechanical switches. The device can also mimic a Surface Dial. Eight layers of mappings. Supports macros.
The software tool for setting up the keys is in Chinese only and it seems they currently only focus on the domestic market. Hopefully they would sell to global markets soon so that you can get and use one.