Shipping issues and fees are bigger orders.

Most of us order from bitmaintech and use ups.

I do every order as a single unit I have purchased 5 or 6 so far 1 at a time and never had an issue.

If you read threads people getting 3  or 4  at a time have had issue.

If you want 4 do separate orders on the same day

I did 2 on one day 2 times