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Not trying to be rude, but if you know nothing about hard drives, my suggestion is that you not replace the HDD on your laptop. Or, if you are intent on doing so, that you wait a year or so until better hybrid disks or faster SSDs come out.
 
I don't know much about UK price. But if you want a reliable SSD, get Intel. The 80GB version cost about 200 usd.
 
That is a very good price for a 128gb but how legit etc is another thing. The seller doesn't have many feedback scores.
 
If you don't know anything about this sort of stuff then you should read up and do research before you even consider buying one; just my opinion. Also, I wouldn't get an SSD from ebay (let alone that specific one).
 
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