Problem starting up rpcs3.exe

Thanks again for the further insight! I looked at the extracted contents of the ISO file inside the BLUS31319 folder and there I found a sub-folder named PS3_UPDATE which contains a single file named PS3UPDAT.PUP with the size of 256MB.
Furthermore, out of curiosity, I did a Google search on PS3 firmware and downloaded yet another PS3UPDAT.PUP file which is labelled as version 3.55 and has the size of 170MB.
So both of these PUPs are now sitting in their encrypted forms on my laptop's hard-drive and waiting for me to take some form of action.
Is it necessary to unpack both of these PUPs in order to make the game run? Or is it OK if I only unpack the first one which came from inside the ISO? If I need to unpack both of them then where would I store the second one?
Last but not least, regarding this PUP unpacking tool and those PIC/PRX/SPRX/whatever library files, is there some kind of official website where I can pay to download all of these items with either my creditcard or my PayPal? Since I would rather just pay for this firmware and decryption stuff and download it straight to my laptop instead of buying an actual PS3 only to return it back to the store on the following day and demand a refund because I'm a diehard PC user who prefers emulation and doesn't want to clutter my house with piles of consoles.
I really hope there is such a website. Please tell me there is.

Unfortunately you can't buy PS3 firmware without the PS3 itself as far as I'm aware.
You can unpack the software upgrades which are downloadable through Sony's website, those "PS3UPDAT.PUP" files, if you're legally allowed to do so. You only need to do it to one file (the higher the firmware version, the better), and then you'll have the libraries to use whenever you need. Use a PUP extractor tool for that effect.
But as you also said, PS3 discs come with a PS3_UPDATE folder which contains a copy of the firmware update the game needs to run. You can also unpack that one.
Again, you only need one set of libraries, so there's no need to be unpacking every game's firmware version and switching game modules.
Just make sure the games you try to play were made for versions below the one the modules belong to.