Youd have to be pretty hard up to sell right now. Either that or they bought at $4.
Human psychology can be a funny thing. Some of these sellers bought for the wrong reasons (they thought silver was going to $100 really fast, etc) and now might believe silver is going to $5 and they just want to get some of their money back. Some probably need the cash too of course.
Some investors get bored and want action, so seeing silver stagnate for a few years and then drop, rinse and repeat, they want the cash to do something else, maybe buy bitcoin or penny stocks, etc.?
I have been buying cool stuff cheap when it is available. Lately I've picked up some nice foreign bullion for $18-$20 per oz (fancy coins in boxes with COA, etc). Many of these coins retail $40+, some higher, some only a few bucks more than what I pay.
I know my dealers pay these folks melt or less (if sterling coins) so they are happy to flip the coins to me for a few bucks over (but I usually am expected to buy the entire lot- I can't just cherry pick the best stuff). None of the dealers I buy from sell on ebay, which is great for me.
I am surprised to see the level of cool stuff being dumped at these low prices. That tells me we might be getting closer to a bottom if collectors are selling their stashes even when prices are down. I don't think all of these sellers are desperate for cash.
I think a lot of folks are so used to low silver prices these days, that they don't care to wait any longer hoping for the big price gains.