Stocks of iPods for various countries
You can write

if raw_input("Enter the country from which you order from") == "Brazil":
    c = 1
else:
    c = 2


instead of

print "Enter the country from which you order from"
x=raw_input()
if x=="Brazil":
    c=1
else:
    c=2


as you are not using x anywhere. I less variable and raw_input has optional string so why not use that?

In function profit instead of using

if y%10==0:
    P=orderfromArgentinafb(y);
else:
    P=orderfromBrazil(y);


you can use

if y % 10:
    return orderfromBrazil(y)
else:
    return orderfromArgentinafb(y)



You don't need the variable P when you are just returning it. 
Why are there semicolons at the end? This isn't C
Notice the changing the order of return. It gives the same result but with one less comparison.


Same thing can be done in function calculate. 

Use if...elif... in case you are just doing one of the things. Using as it is leads to more comparisons than are needed. 

In both the functions orderfromArgentina and orderfromArgentinafb a simple reordering of statements can lead to removal of additional variable Cost.

You need to read a style guide. Check for official tutorials of Python. They contain brief style guide. That is also an optimization. It doesn't effect memory or time complexity but it leads to better maintenance