Because physical silver is MONEY.
i.e:
a medium of exchange; transportability, recognisability, resistance to counterfeiting.
a unit of account; It's divisible, fungible, real, measurable.
a store of value; its use in technology worldwide makes it directly (rather than indirectly) proportional to the value of those items and the things they produce, it's rare, and again real.
[Rant]
If you want to 'speculate' on the value of silver on the market, then best price in the risk of being manipulated out of your money. And know you'll deserve to be hit with 'capital gains' tax, if you manage to beat the market forces at their own rigged game.
If you want an alternative to storing the 'value' you have 'earned' in society from working ( supposing you do ), in a tangible possession that you own, who's value cannot be reduced to 0 in an instant, or over X many years, then we have gold and silver for sale here at bargain basement prices. ( except in the case of a tyrannical desperate controlling government decree, in which case your stack is the last thing you should be fighting for.
And then you can complain along with the rest of us that the supposed 'capital gains' you've 'made' (ha!) people see is the spoon bending in the light of inflation. but still don't expect to win that fight without an argument...
Wow, [/Rant Over]
Seriously though, DYODD ( Do your own due diligence )
Both options have their advantages, but I would recommend getting something real and holding onto it first, You will be surprised what holding onto your first 'piece' of real money feels like.

Have a good read of posts dating around key market events to see peoples sentiments, come up with a medium/long term plan, and keep your eyes, ears and mind open.
Eventually you will come up with a strategy that suits you.
That is the best advice I can offer.