The paint/color fading is purely due to rough usage. Just use a back cover or use with care!
If you're gong to buy a new S2 from Pakistan then I'd suggest that you should go for HTC because in Pakistan only I9100G is available, not the original I9100. And do search about I9100G on the internet (xda and other forums) because there are many complaints about the G variant.
I was out to buy a new S2 a few weeks back here in Lahore and found quite suspicious (apparently) things going on about S2.
If you'll ask for simple I9100 then you'll be shown a box of I9100 but warranty will be from some "telekom" company and you'd be told that warranty will be honored officially by Samsung. However, Samsung hasn't mentioned telekom anywhere on their website. Also, there'd be no surety that it will be I9100 in the box as many Indians shown on the internet that box of I9100 contained I9100G.
At another shop I was shown a box on which the model I9100M was written at back but on a printed paper, where IMEI# is written on box, only I9100 was written and shop guy didn't even notice that.
So, I suggest you that you either buy S2 from abroad (ask your friends/relatives to send you) or go for a slightly used one that came from abroad (you can get one in mint condition in 39-41k) or wait for the S3.
