Ok bro I don't know where you're coming from with that but I highly doubt that increasing 6gb of RAM will improve his gaming experience in a significant way... And by the looks of it he probably uses this PC for gaming since he is willing to buy a PS3 in exhcange.... Plus how did you come up with nVidia being the "cheaper alternative"? ATI/AMD has always been the cheaper(therefore better) alternative plus a lot of them take less wattage out of your PSU than nVidia cards... nVidia is only better when you're doing enthusiast level of gaming...
The truth is this guy has a fairly decent rig that will perform better with a GPU upgrade... Plus SSDs cost a fortune...
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I think you should just focus on upgrading your PC rather than getting a PS3 unless you go for a PS4 which is better than all other options...
And when you're buying an ATI/AMD card... just remember this...
In the four-letter model #:-
The first number(Xxxx) tells you when it released and what series its a part of(generally newer is better but not in all cases as they are unnecesarilly costlier)...
The 2nd number (xXxx) tells you what level of gaming you can do with it (i.e. your current card 4350 can do level 3 of gaming which is almost equivalent to any on-board video card)... This is the most important number in the whole model and i think anything with x6xx or x7xx in it will suit you PC rig... x8xx will only bottleneck it so no point in that unless you plan on upgrading your CPU also...
The 3rd number (xxXx) points mostly about how much memory, clock speed and other things this level of card possesses(anything below xx6x is low-level).
The 4th number tells you whether it's a card for desktops(xxx0) or laptops/integrated (xxx5)...
This is all you need to know about ati cards and remember do NOT buy cards according to their "memory"... even 2gb video-cards exist which are entry-level and won't give you any gaming at all...