sixgun

There are a couple of things to consider.

Silver often milk spots - this will destroy your premium silver as effectively as it will generic silver. When silver is near spot, little to no value is lost. Premium silver loses most of its premium.

Silver has been low priced for years. When it stays low price, generic silver doesn't appreciate. Over time premium silver becomes relatively rarer and so the price of a collectible piece rises. HOWEVER if the actual price of silver shoots up then i expect your percentage proft will be more with generic silver.

BYB's logic holds on past performance and will do until silver breaks out hard.

Dealers withdrawing 'stock' over the weekend is not shady practice. They are taking down items for sale - not necessarily withdrawing stock.

If they advertise and sell silver they don't have and the price jumps they will get screwed. Andy Schectman of Miles Franklin said in an interview on Arcadia Economics, they were selling so fast they ran out of stock and did not have enough price hedging for new stock so they stopped selling - he says he was out $40 000 when the price jumped after the weekend.

#sliversqueeze continues and is accelerating - 

https://www.reddit.com/r/Wallstreetsilver/ 

has over 30k followers now - when i first joined it was just over 2k.
Big Twitter craze to promise to buy PSLV shares if someone gets more followers. 
Silversqueeze has only just begun. These people are buying physical and buying PSLV - they can't get squeezed out.