Upgrading a Prebuilt PC Questions

Hello everyone I am new to the forums and I saw no section on pre-built gaming PCs so I am just going to post it here. I have been doing research on building PCs vs buying pre-built vs buying a bare-bone kit. Disclamer right now, I don't want to build a PC myself I would rather have someone build it for me and have a warrenty with it so I feel safer using it. I have this link to a refurbished PC for around $270 it has basic components but IMO a good starting point. I want to upgrade this machine so I can run games like Guild Wars 2 at medium settings in WvW at good frame rates. Also to be able to  render and record my youtube videos at high quality

http://www.amazon.com/Gateway-DX4375G-UW20-Desktop-processor-Windows/dp/B00EUQTSZI/ref=sr_1_3?s=electronics&ie=UTF8&qid=1390850187&sr=1-3&keywords=Gateway

If I could get some advice on what to add in so I can max it out as much as I can at the maximum $150 budget for adding more to it. Like a new graphics card or APU and a new power supply, and maybe more ram.

Thanks :)

just throw in like a cx430 power supply and a HD 7770 and you should be set to play some games

Since in this build and its an APU am I limited to AMD only or can I add a nvidia graphics card? I've happy with nvidia with the laptops I have and I am not sure how good AMD's tweaking program is.

 

you can put a nvidia card in there too if you wanted.  If you are going nvidia look at the 650ti or 650ti boost.

Looking at the prices this is a bit more in my range since I still need to buy a monitor+ the power supply. Will this run at decent framerates on 1080p or 720p? For GW2 and maybe BF4?

http://www.amazon.com/gp/offer-listing/B0089KJQFS/ref=sr_1_4_olp?s=pc&ie=UTF8&qid=1390859436&sr=1-4&keywords=gtx+640+2gb&condition=new

it is playable but it depends on what do you mean by decent frame rates? 30FPS? 60FPS?

The GT640 may play BF4 on 720p but struggle on 1080p if you are not bother with the low graphics settings However, it is better to increase your budget to get a 7750/7770 for 720p. For 1080p, probably 650ti or higher 

I would say 30 fps for me. I will consider getting a 650ti

Remember to throw away the PSU in the case and get a better one : cx430

Also check if the case has enough space to put in any GPU you plan to put in once you got the PC.

Check if the motherboard has a PCI Express X16 slot

650ti would be the choice of the GPU in this price range. Any lower and you won't have anywhere close to a pleasant gaming experience.

Also, +1 on a better power supply.  The ones that comes with prebuilt systems are pretty much crap.