Rookie Here Who Needs Some Help On A Dicey Situation With A Coin Shop!

I sold 100 oz. of silver on Monday without showing any ID. I don't think that is so uncommon.

Yes it is very uncommon and probably a violation of a City bylaw in 99.99 % of most civilized places in North America.
There are even HOLD requirements in a lot of cities of up to 30 days .

Exactly. The shop where I buy from quite a bit has to hold anything they buy over the counter with any precious metal content for 14 Days (Plus have a photo ID of the seller on file)

You may not have known the value of your silver before you sold it but you most certainly are aware now that the buyer made a huge mistake and paid you Double the going rate.
The Honest and Right thing to do is to accept the extra $200 or give the money back in return for your Silver.

My first question, (and I am a suspicious person,) is why did he split the payment and not give you all cash or all check? Best case scenario is to return the cash and check and receive the same silver in return. I hate these confrontations, but if left unattended, it only encourages them to do the same thing to another guy. I hope it works out well for you, it was not your mistake. Surely if you had sold it for way less than market value, you would not have the advantage of a Frustrated Contract.

I dunno. my local coin shop would bend you over to screw ya if they could. let's say they way underpaid you... would they make it up to you? I doubt it. I really do.

personally, I would just split the difference. like the man says, if an atm starts spitting out $20's, it is not really yours... but still, he should pay something over and above what it was really worth to compensate you for all the trouble it caused you.

at my shop you need an id for any kind of transaction, and it is written out on the receipt so as to minimize any slip-ups.

I am not saying you should be able to keep ALL of it... but I am saying that if he sized you up as an ignorant and paid you only $10 an oz., I doubt that the shop would make it up to you to even near spot price. so why should the shop get clean away?

at my shop, they are pretty clear of what they will pay by way of a large billboard and signs, so it is hard to make an error on either side.

if you take him to court for the whole amount he paid you, the judge will problably think you are greedy and rule against you.

If you sell 50 things, but get paid for 100 things, you are not entitled to the money for the extra 50 things. Making an over payment, does not mean the receiver gets to keep it.

It is not the coin shop's fault if the seller spends money they should not have been paid, then gets burned with fees because of it.

I think the seller (husker) came here looking for support for the idea that the buyer (coin shop) shouldn't have the right to stop payment on the check. I do not buy the fact that because someone is "new" they "had no idea" that their 50 troy ounces of silver wasn't worth $1,650 instead of $825. The price of silver is readily available and so are calculators.

I have the feeling that the seller knew they were overpaid, and perhaps spent that money wrongly thinking that it wouldn't be recoverable if spent. They wouldn't be in this position if they had let the coin shop know that they were being overpaid.