Customs duties and taxes

I went to the post office here in my town to claim for the package sent by my sister from Australia. The package is all about books, shirts and a little bit of toys. I knew that the post office usually charge 40 pesos per box claimed and that is with official receipts; when I presented my Identification card (Drivers license) along with the post office claim papers, a guy who is from custom computed that amount and he said that one of the cartons is taxable because it contains toys and he kept on computing until her derived from a four digit figure amounting to 4,456.00 pesos. I asked him if that's the final amount because before when my sister sent some packages, I never experienced the way that I experienced this time. The guy ask e if I can pay the amount but with added offer saying that if you can't pay the amount we can always go down to a better offer asking me if how much can I provide for the taxes but with no receipts. It sounded too bad for me since I always want to transact cleanly but this time i grab the opportunity and offered the guy one thousand pesos only and luckily he accepted my offer. I am quite surprised because how can he lower the cost if that computation he made was the exact and the right amount for my package. This time, I proved it right that's why most of the people said that the most corrupt agency of the government is the customs followed by the LTO (land transportation organization.