Wedding Photography Cost Calculator
Well, this code has a few problems:


Typing non-numbers twice in a row causes a ValueError.
It is not quite PEP-8 compliant (the official python style guide)
No docstrings
Final bit of code should be wrapped in a if __name__ == "__main__": block to add reusability.
It is not very reusable




Now let's fix all that:

Wrap your input section in it's own functions like this:

def get_num(prompt, errorMsg = "I'm sorry, that's not a valid number"):
    """Returns a number from the user"""
    while True:
        try:
            input = int(raw_input(prompt))
        except ValueError:
            print errorMsg
        else:
            return input

def get_yes_no(prompt, errorMsg = "I'm sorry, I didn't catch that. Could you try again?"):
    """Returns True for yes, False for no"""
    while True:
        input = raw_input(prompt)
        if input.startswith('y' or 'Y'):
            return True
        elif input.startswith('n' or 'N'):
            return False
        print errorMsg


This allows you to have more robust and more readable code

Naming: function names should be lowercase and separated by _. So wedcost(hours) becomes wed_cost(hours). 

Also your function doesn't do what is advertised, since it keeps on recalculating.

Let's wrap that into a main function like this:

def main():
    wed_cost(get_num("How long will we be on location? "))
    while get_yes_no("Would you like to recalculate? ('Yes' or 'No') "):
        wed_cost(get_num("How long will we be on location? "))
    print "Have a nice day :)"


Then we can add this little bit of code to the bottom:

if __name__ == "__main__":
    main()


Which will run your code if it is directly called, but also allows you to reuse this code elsewhere with an import without causing any code to be run.



Finally let's put all your magic numbers (such as 75, 100 etc) somewhere more recyclable by defining some constants at the top of the code:

MIN_FEE = 250
HOURLY_FEE = 75
OVERTIME_HOURS = 6
OVERTIME_FEE = 100


Then the wed_cost function becomes:

def wed_cost(hours):
    """Prints a message with the cost of a wedding shoot given a number of hours"""
    totalCost = 0
    if hours &gt;= OVERTIME_HOURS:
        totalCost = hours * OVERTIME_FEE
    totalCost = max(hours * HOURLY_FEE, MIN_FEE)
    print "The total cost of our services will be ${}.".format(totalCost)


This makes your code more understandable, and more debuggable :)