Caveat Emptor!
Folks when it comes to "traditional" muzzle loading I see all sorts of "odd" prices. Some folks are ignorant; some folks are
nuts. 
For example, I've seen very ornately carved long rifles offered on a reputable website, for a couple thousand dollars, YET..., when one looks at the close-up photos of the lock mortise where the lock joins the wood of the stock, one can sometimes see very obvious, rookie mistakes (imho). Either the wood to metal fit is poor, or the builder used a precarved stock and failed to properly shape the mortise flat to the rear of the lock, OR BOTH. The builder did a wonderful job on the carving, but rushed the beginner stuff to get to that task..., well if you haven't mastered the basics, in my book, you should not be charging top prices. Folks PAID for those flawed rifles, in part I believe because of the website where they were offered, and because the buyers didn't know better...thus causing the trend to continue.
When it comes to used guns, folks think they know, OR they are trying to BS the buyers. They don't do any research to see what's "the going rate".
I've seen used Pedersoli muskets priced MORE than a new Pedersoli musket kit. So they think the buyer will buy the old musket (without warranty) instead of building the new musket, AND they don't check to see that when the factory muskets go on sale, they cost only about $200 or so more than their overpriced used item.
So eventually some fool comes along and buys the item...or they get upset and take it off the market.
Further, they often say they are the original owner and you can see the serial number..., you can check when the musket was made and you can check the price
back then..., duh..., so you offer the guy 2X what he paid for the musket, and they want more like $300 below the factory price of the new gun (which is like 3x price they paid).
It's not a collector's piece, they are still made, but they think they have some sort of precious jewel or somehow the Italian overpricing = they should get more for their used piece. (OK once in a great while the guy doesn't really want to sell his gun, for various reasons, offers it at a really high price, and IF he gets that, well in that case he'll sell..., but those guys are rare imho)
Then you have unscrupulous "dealers". Mostly I see these folks selling "antiques", not gun dealers. They rip people off with their other stuff, such as china and furniture, so they think they are smart enough to do it to gun buyers. I've seen folks try to sell repros as "originals", and a
red flag is when they say "I'm selling this for a customer [or estate etc.] so I can't answer many questions about it". Like the time I saw a $1000.00 price tag on an antiqued pair of "Confederate Navy .44 revolvers" with the Italian proof marks clearly visible. Or when I saw a modern restocked 3rd Model East India Company Bess being sold for $3000 because it's "original", when you can buy such muskets in a sort of kit (which this clown obviously had done) online.
And Montess85 is right, when you point out the flaw to the seller, they get pissed off. Had a guy selling a "new" Bess, which was actually a used barrel and other parts that were new in a new stock, but the dumb-ass forgot to leave room for the bayonet when he put the parts together..., the stock ran out to the muzzle of the barrel, and when I pointed it out he started shouting at me (got his hand caught in the cookie jar
).
So bottom line,
BUYER BEWARE.
LD
I did come across a Pietta 1858 Remington on a table at a small gun show. It had an old Navy Arms box but nothing else. The cylinder had a drag mark and the nipples were a little flattened from dry firing, but the wood was beautiful, exceptional bluing and a great trigger. I was in the market for another one to shoot blank charges for some shows and they guy said he wanted $125.00 for it. This was 5 years ago and Cabela's was around $200.00 new by then. I picked it up and took it home.
