Avoid buying from companies based abroad.
If things go OK then it's fine but, if something is faulty and/or requires returning, then the resulting problems will haunt you.
Kingston is a respected memory manufacturer but this is an auction and you won't a) know how much it will eventually cost you (plus p and p) and b) you might not even be successful.
At the moment memory is starting to go up in price again - 256MB DDR memory costing £26 at the beginning of this month is now up to £32 at one major online supplier - so it's worth checking out dabs, Scan, Novatech etc for prices quickly.
Alternatively buy on e-Bay at Buy Now! prices, but I would avoid the US based offers.