I went to go buy 4 rocket boxes today but the 450 dollar shipping on them turned me away 
That's ridiculous. They are eitHer taking a profit or paying retail. My FedEx acct would be $25-30 per. Really you can ship 7kg from China to USA for $30 usd ? Nice! But how long does it take though?
I can ship for $6 per kg UPS but it takes 7 days. The fastest service is more expensive but it only 2-3 days.
Express International is usually 3-4 days. Quicker from Europe, but this is China.