No, you should not pay for taxes / customs / duties for imported books or books shipped to the Philippines.

A few entries back, I posted my experience with The Book Depository, which was 100% positive. They offer free shipping to the Philippines and the package was delivered straight to my doorstep. My second package - a pre-ordered copy of Hot Dudes Reading - also arrived safe and sound, and yes delivered to my front door, too.
However, our THIRD package...ah, well, that's when I had an "encounter" with a customs officer of Pasay City's Post Office.

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Our authorized staff went to Pasay's PO to pick up our TBD parcel. To be honest, I'm not even sure why we had to pick it up in Pasay when we live in Quezon City, and - believe it or not (sarcastic) Quezon City has its own post office, too (Also, I love QC's post office. I've never had any bad experience with them).

Here's TBD's official receipt.

Let's say the exchange rate is P47, so that's P4,319.3 when converted.
However, custom officer thinks differently.

The price of the boxed set ended up P7.7k+​!!!!
Even worse, the officer is charging me around P1,308, which is approximately 30% of the price TBD charged me for the boxed set.
Our staff called us, asking if he should pay for the taxes, and I said no. I told him to inform the customs officer that I'm a registered author with the National Book Development Board so I definitely know my rights, and as such I know that I can't be charged for any customs / duties where books are concerned.
Custom officer then told our staff that the rule ONLY applies to "educational books and cultural materials".
To emphasize (read: IMHO, parang gusto niya pa mag-mukhang tanga ang staff namin, but hey that's my opinion and sige, baka gusto niya lang maging properly informed ang staff namin), binigyan pa yung staff namin ng photocopy of BOC rules, with the appropriate text highlighted and encircled.

Talaga lang ha.
Eh bakit ito ang sabi ng NBDB in its February email to me---

Above document clearly states that it doesn't matter how the books were acquired or shipped. BOOKS ARE TAX OR DUTY-FREE for as long as they're not more than the specified number of copies and they won't be used for advertising purposes. Our boxed set consists of various titles and it's for a personal collection (for my boyfriend's sister, actually, who's in the process of building her own home library). Also, nowhere in that document states that the books have to be educational or cultural in terms of content. Rather, the law concerning this (and I'm speaking to you, customs officer) is the AGREEMENT ON THE IMPORTATION OF EDUCATIONAL, SCIENTIFIC, AND CULTURAL MATERIALS.
Aaaaaanyway, I told our staff not to bother paying for the parcel and simply ask for the officer's name.
Ayaw ibigay.
#alamnathis
​Following this, I then asked for my lawyer aunt's help and forwarded her all the necessary documents concerning my package. FYI: I am not the FIRST VICTIM of this type of...umm...encounter. Here's one reported by a netizen and shared by When in Manila, and which I also forwarded to my aunt.
Result:

I SWEAR TO GOD, SA SOBRANG INIS KO, KUNG HINDI PA DIN NIYA IRE-RELEASE ANG BOXED SET NAMIN, MAGKAKADEMANDAHAN TALAGA. To be honest, if they had just charged me P500, I would have paid even knowing that I didn't have to be charged. I know that's not right and that would mean encouraging this practice to continue, but that's what disappointment and frustration can do to you - sa bwisit mo, you choose the no-hassle-way out, even if it's wrong.
But...
Sobra naman kasi yung siningil. Even if we could afford it, nakakainis na approximately 30% of the retail price ang nicha-charge. Parang sobrang...umm...there's just one word that comes to mind, but huwag na lang natin gamitin.
Baka...hindi talaga naintindihan ng custom officer yung rule about books.
Pero...
30% of retail price talaga ang tax?
No comment na lang.
​Anyway, going back to the story, we had our staff drop by the post office again, this time armed with our politely worded legal letter.
Result:

I am not the kind of person to make waves. In fact, I am so ridiculously shy I avoid public appearances (as an author) at all costs. However, I feel that this is something I should share in case other people find themselves "encountering" the same thing. Paano naman yung mga bata na nag-save ng sarili nilang allowance to buy the books they love? Tapos icha-charge ng ganito? It's not right, not fair, not everything - which is why I'm also sharing my experience (just like the netizen with the Harry Potter boxed set) in hopes that it would give others leverage of some sort or just confidence even to let customs officers know that their book purchases shouldn't be subjected to customs / duties.
End of rant. >.<