Buying Canaan Avalon ASIC miners

Hi guys, total n00b in mining game. I have 3 helium miners on order and I want to order ASIC miners now, been thinking to order them through canaan’s official website, is that a good idea? Any chance I’ll get scammed?
The reason I want to get them is that they are more reasonably priced.
Also I wanted to ask another question, can I unplug the ASIC miners for a short time and plug them back again or that is not recommended?