You must cast the inputed strings to floats:
print "Welcome to Jaap's Hard Drive Calculator"
price = float(raw_input ("What is the price of the hard drive you intend to purchase? Please do not type GB or TB at the end."))
model = float(raw_input ("What is the size of the hard drive you intend to purchase? Please do not add the currency symbol."))
print "The cost/GB is", price/model
print "Thank you for using Jaap's services"