Coinbuf

Thank you, those are much better, but alas as greenstang wrote these new photos prove that the coin has indeed been plated in the past.

Your coin is not one of the so called SMS coins, just a normal brilliant proof.

Thank you, those are much better, but alas as greenstang wrote these new photos prove that the coin has indeed been plated in the past.

Welcome to the forum, sadly your photos are woefully inadequate for anyone to give you an in depth evaluation.   But what I can see from them and using your description, is a coin that has been plated in the past as a novelty item.   That takes all the numismatic value out of the equation and leaves you with a value of approximately 3 cents for the copper metal in the coin.
There is no way to opine on values you have seen online without knowing what and where you have been getting your valuations.   However, it is not uncommon on sites like etsy, ebay, FB and others to have sellers that post outlandish prices for common and even damaged coins.   Some are pure scammers out to land a big fish, some are just completely clueless and do not attempt to actually find out what they have or what it is really worth.
As already noted above the 1930 cent produced in Philidelphia is common and does not command a high value unless in exceptional condition.   This surprises many non collectors as many equate something that is nearly 100 years old as being valuable.   In numismatics the age of a coin is only one part of valuation, condition of the coin, rarity of the date, and survivability of the date all play a part in how valuable any coin is.
I will leave you with this screen shot of a 1930 cent that was graded by PCGS (in case you don't know PCGS is another firm like NGC) that sold for just $55.   That may seem like alot for a single coin but consider that the grade of MS65 is a high grade, and it would cost close to $50 to send a single coin in to be certified and graded by NGC.

Thank you, those are much better, but alas as greenstang wrote these new photos prove that the coin has indeed been plated in the past.

1875 twenty cent piece (much scarcer than the 1875-S), PCGS graded AU details, cleaned:

I would avoid Littleton and Ampex, imo their prices are retail+ or higher.   For slabbed/certified copper cents, two cent pieces, and buffalo nickels I highly recommend AngelDees.  Link   Andy does tend to focus on the high grade coins (as most dealers seem to) but he does have some select lower circulated graded coins too.   He is one of the top Lincoln specialist dealers that I know.   For raw coins if you can find a local dealer that you like and trust I have found that to be good source in the past.

An abused entry in my 7070 set.

Plated, mercury plating was done often in schools for chemistry class.   Nickel plating is another possibility as the guys that work in chrome plating shops love to have some fun and nickel has a weak attraction for a magnet.   As Neo suggested whatever was used to plate the coin has begun to wear off over time.

Looks plated to me.  The toning could be copper peeking through under the plating.

Does not look like a DDO to me, plating blister or die damage is more likely.   Bob's advice to post on the CONECA forum is good advice, if they think you have something they may request you send in for an in hand review.

An abused entry in my 7070 set.

Your coin is not one of the so called SMS coins, just a normal brilliant proof.

An abused entry in my 7070 set.

Hello and welcome to the forum.  

An abused entry in my 7070 set.

An abused entry in my 7070 set.

Your coin is not one of the so called SMS coins, just a normal brilliant proof.

1885 Liberty nickel, now NGC graded XF 45: