Well silver is very high at the moment. It's trading at approx 720 Euros per kilo today (Dec 2010).. it was as low as 430 / Kilo a few months ago (August 2010). So 50% gains in a few months are possible.
Costs and fees seem quite high. Have you considered other options, for example, coins?, or a place like BullionVault or others?. If your silver is 'unallocated' then you don't own it... you are owed it by a company... if the company goes bust you must wait in line for your money, which might not be available.