The only issue with ordering directly from Bitmain is that they don't take PayPal, only Bec and I don't have any since I am new to this. Plus PayPal is very easy to use.
When I need Btc, I just go here and find some to buy:
https://localbitcoins.com/I find paying a little extra for the Btc is cheaper than buying form someone with Paypal.
Check it out for your self and see which way would work best for you.