will increasing the ram improve a game fps? or is it solely based on graphic card
If I remember correctly the effect of having say, 4GB and 6GB or even 8GB of RAM on gaming is negligible. But then again I'd say 4GB of ram is the bare minimum on any machine. My 2 year old main rig still uses 4gb of ram and only in very intensive game I'd see my RAM usage up to ~90%, otherwise for daily usage it works perfectly fine. Pretty sure there are benchmarks on 4GB of ram vs 8GB of ram on gaming, just google it if you're interested.
You will see a MUCH more significant difference in gaming if you upgrade/or add your video card.
You already have a HD 5450 install? Then if you want you can replace it with a more powerful one. But if you're correct on your PSU being only 250W, you don't have a lot of options for medium-high end video card. TBH a $100 budget is not that much to upgrade your existing setup. Have you consider getting a part time job, save up $800 or so and get a brand new machine (or even lower if you salvage from your current rig)
