Your name says Asic supplier, if this is your side job why are you asking this question then? Every miner starts mining Bitcoin to make profit or to increase their stash of Bitcoin, some are doing it for fun while some are serious miners that dedicate their lives to become a long term Bitcoin miner.

Most people prefer playing safe, so they go on official asic builders like Bitmain to order for their miners, and those who are ready to take risks go for used asic miners, remaining focused on China, I've help few people ordered on Aliexpress and I did this base on verified buyers review.

Whenever I want to shop online I always look into how many asic a store or supplier has sold in the past years and I also make sure they have loads of successful business reviews from their customers.