Old laptop vs. many new.

hi guys.
I have a question im hope you can help me answer.
im a grad student and most of the work on my old laptop was word, excel, powerpoint etc. I do some stata(a statistical package) which is pretty much just black and white graphics.
so heres where my question comes in. my old laptop screen died one me a few days ago. the repair is about 200-300 bucks. im trying to figure out wheterh i should repair this laptop or buy a new one.
considerations are.....
is this laptop still better then budget laptops now

can i play occasional games such as gw2 witcher 2 alan wake on my old laptop or a new budget one, which would perform better.

and will normal everday use be better on this or an new comp

here is my old laptop
its a dell insiron m5010
it has 4gb ram
amd phenom 2 n930 quad core 2.0ghz
64 bit op windows 7
and lastly the craphics card is a Graphics Chipset ATI Mobility Radeon HD 550v
Memory Size 1024 MB
Memory Type DDR3
Core Clock in MHz 450 MHz
Memory Clock in MHz 600 MHz
Total Memory Bandwidth in GByte/s 19.2 GByte/s

now im not really a expert with laptops so im not sure if i shoould keep this laptop or go for one the following laptops.
(my budget is 300-450ish.)
I understand the 3rd gen intel i processors are better then the amd a in most cases so id like a 3rd gen 15 over an a84500m and that intel hd400 graphics cards suck compared to ati radeon 7640 and NVIDIA GeForce GT 630M.
what graphics card is better out of the ati radeon 7640 and NVIDIA GeForce GT 630M.
plz correct me if im wrong on this info and give me opinions on which laptop is best according to my considerations and why.
thanks all guys and hope to see your opinions

samsung
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

dell
http://outlet.euro.dell.com/Online/SecondaryInventorySe...

dell
http://www.currys.co.uk/gbuk/hp-pavilion-g6-2210sa-15-6...
(better proccesor and ok dedicated ram?)

hp
http://www.currys.co.uk/gbuk/hp-pavilion-g6-2213sa-lapt...
(alot of dedicated ram?)

open to other suggestions as well
thanks again