Package arrived today safe and sound. Totally recommend AliExpress standard shipping:
Pakistan Post tracked the package from Singapore to my doorstep. Very impressed! The postman took my signatures before handing over the package. He was very professional and didn't ask for a single penny.
The CPU came inside a tough plastic case, which itself was covered in lots of foam, despite its meager $8 price-tag! The seller went at length to ensure the safety of the CPU. Impressive.
If anyone's interested in ordering an Intel CPU then I'd totally recommend this seller:
https://chenmansu.aliexpress.com/store/1953865?spm=a2g0o.productlist.0.0.59025eb06GLyYN
The CPU came with a stamp which probably means they tested the CPU before shipping it.
P.S As it turns out, IMO letter means that Pakistan International Mail Office has cataloged your package as a "letter" which is a good thing because you won't be charged with any additional fees or custom duties etc!
I think it said "IMO (Parcel)" when I ordered the GPU, and then it got stuck at customs and then all hell broke loose!
Anyways, that's pretty much it!