All in all if you say that puppies are £2000 here and in Cameroon chi are £320 then you add on the £2000 for quarantine. It doesn't take a genius to work out that you could buy a good decent puppy here for £2000 and end up spending £2320. Don't forget how much it will coast for shipping. You will have to have the puppy in quarantine for 6 months. You also have to think about where the puppy came from. Was it bred for the money? (Which by the sounds of it was) What is the puppy's health like? And most importantly have you seen the parents? As that is so important when you by a puppy.
Please don't buy a pup from there but wait you have the money and go on a breeders list and wait for a lovely healthy puppy. Or you could always go to a rescue centre a get a lovely little dog. Please have a look here at the Chihuahua rescue page
http://www.the-british-chihuahua-club.org.uk/Rescue/InterestAdopt.htm here you could give a Chihuahua a good home.
Just please please please don't go and buy a puppy from Cameroon.
Sarah xxxx