Ret is right. It is not against the law, but if you are sending $3K a week then yes, they might be suspicious.
A. make sure your source has made it almost impossible to be traced (you send your money to john doe in Cali and your package comes from a john doe in cali to your address you have on the WU form, that would not be too smart b/c if the DEA gets a tip from WU then they pretty much have the package delivered to you on a platter for them)
B. Send in one payment maybe 2 if it is seldom. (If you have to send over $4K then maybe you should order your stuff 2 or 3 different times and not all at once, b/c they see your name posted 2, 3, or 4 times with in an hour of eachother sending $999 each time to john doe in cali, then you will be flagged like Ret just stated)
C. make sure your package comes to a different address from the one on the WU form (definitely not any known addresses with your name, parents house or your own residence. Have a great g/f that lets you send the package to her place

)
D. Make sure your source will allow overnight delivery.
So, make sure you use your real id and a real phone number and address b/c if you don't and john doe on the other end goofs or WU goofs and you have to resend, then you will be out of cash and AAS.