That's a very good price for a i7 3630qm. It is a much better (quad core) cpu and it would fit in your socket. There are 2 issues though that I can see.
1. your current processor has 'sandy bridge' microarchitecture whereas the i7 has 'ivy bridge'. They are very similar however so my 'best guess' is that the bios would be ok with this upgrade.
2. Your current processor is 35 watts - the i7 is 45 watts. More watts means more heat. Many people would say that since your system has been designed to cool a 35 watt processor ... putting a 45 watt in it would be a mistake ... it would run too hot. However, I've replaced many 35 watt cpus with 45 watt ones and never encountered a problem. If you were to try it, you would definitely want to carefully and completely clean the entire cooling system when you replace the cpu.
Overall, I would think that this upgrade would work but ... there is no way to 100% guaranty this. On the plus side - you're getting the i7 for a very good price - the bios will either recognize it or not - and if it does - it will either run too hot or not - neither will hurt anything as long as you don't repeatedly overheat it. A good temperature monitoring program will allow you to keep an eye on the cpu temps. If things don't work out ... you can put the original processor back in and sell the i7. If it does work ... you would have a vastly improved laptop.