As much as a piece of string.

The real question is: how many games are you planning on buying?

well this thread is about best bang for your buck so how much would cost a pc to let's say to equally play all games avaiable for ps3 and pc as good as a ps3? so that we can make a better decision what gets you the most for the money you spend hence best bang for your buck.

Still doesn't sounds as easy as with the 360 where you can easily exchance any file you want between a external and internal HDD.  Plus the internal HDD is super portable also and can be easily transfered from one 360 to another 360.

Um, I didnt even know PS3 had PS1 compatibility. Just shows how much I would use a service like that. And I have played my games solely on PS3 between 2009 and 2013.

why not ? it plays all PS3 games from all regions too

Different strokes etc. TLOU and Uncharted are indeed amazing games but not everyone likes that style of game. My point was that a person can't simply state that a console or game is going to universially appeal to everyone because everyone has different tastes.

And how much do all of the games cost, on top of the price of the device of choice? 

You have to buy the games to play them.

not much? if you buy your games wise for your ps3 you don't have to pay that much many games I got didn't cost more than 3 or 5€ and I don't need to look at steam to know they can't be that much cheaper there, if you go physical of course it is a bit higher, but here you can also buy your games used without spending that much money on them.

so for the third time now how expensive would it be your pc? to discuss the topic of this thread (best gaming "device" for your bang of buck)

I don't doubt there are $5 PS3 games laying about, but how many of those are the decent or recent titles? Also how much for decent PS1 games? Most of the games you'd want to play from that era are commanding collector's rates now. 

If you're wise with PC game purchases, anything preowned is worth pennies (just have to hope for a valid serial key) and new on Steam doesnt cost much more. Even better are the games bundles for a few dollars, the current humble bundle has Civ V and Beyond Earth (amongst others) for $15.

The same could be said for hardware, if you're happy with preowned it significantly lowers the price, particularly seeing as you don't need top of the line components to play most games at the moment.

Well I got many games for 3,5, 6€ in my germany (europe) store (I don't even buy that much digital games) the offer is even bigger (more games, and less expensive) if you buy in the american store with a usa account.

If the crash bandicoot games are decent 5€ for each of them

https://store.playstation.com/#!/de-de/suchen/q=crash

all Spyro games for 5€ each

https://store.playstation.com/#!/de-de/suchen/q=spyro

but good that we can agree that the ps3 is the best gaming device to get^^ that's something ;)