love_2.py

DATA = {
    "A": {"unlimited": 70, "package": 50, "extra_mile": 1},
    "B": {"unlimited": 140, "package": 100, "extra_mile": 1.5},
}

DAILY_MILEAGE_LIMIT     = 200

mileage = input("Mileage? ")
duration = input("Duration (days)? ")
category = raw_input("Category (A or B)? ").upper()

price_unlimited = duration * data[category]["unlimited"]
price_package = duration * data[category]["package"]
extra_miles = mileage - duration * DAILY_MILEAGE_LIMIT
if extra_miles > 0:
    price_package += extra_miles * data[category]["extra_mile"]


print "Best option:",
if price_unlimited < price_package:
    print "unlimited ($%s)" % price_unlimited,
else:
    print "package ($%s)" % price_package,
print "that is to say $%s saving" % abs(price_unlimited - price_package)

Parfait!

Regarde le commentaire du programme d'Étienne pour la version longue ;)