This looks very much like the international credit card scam other dyers have warned me about, involving the use of stolen credit card numbers and, ultimately, a large loss taken by the small business owner when the credit card charges are disputed:

Dear Sales,
I'm highly interesting in purshasing the folloowing
product in your store.They are listed below,
 
TIE AND DYE TEE SHIRT LARGE...............400qty
 
Then i will like you to calculate the
total cost of Button them including shipping cost to Lagos
Nigeria . I will then
send you my credit card details for the mode of
payment, Then i will like the goods to shipped via
ups or usps 3-5days express shipment
and ship to the above adress
14 cash street off palm avenue
street mushin, Lagos
state 23401
Nigeria
i will like you to contact me via phone if you
would be able to call me
this is my mobile number and also my fax number.
mobile...2348023267750
fax-----17752061969
I will like to hear from you soonest.
best regard
faith

The fact is, I am not selling any shirts at all - I do not even have the time and energy to make all that I would like to for my own friends and family - so I don't know why anyone would try to buy 400 tie-dyed shirts from me.