All I know is that Palmetto was an Italian repro maker who built the highly regarded Garrett Sharps rifles. Unfavorable exchange rates hurt sales and Frank Garrett quit dealing in them. Some Palmetto rifles were sold here for a while by other importers Like Allen, but apparently not for long. Mr Garrett said that Palmetto sold their tooling to Pedersoli who still does a good business in Sharps copies.
$2495 sounds like a lot, even for a low production item, but when you consider that a plain vanilla Pedersoli runs from $1150 up to $2250 for one with some engraving, it might not be too far out of line.
As to the Gemmer Sharps itself, Mr Gemmer bought the Hawken shop in 1865 and kept it in business for some time. The muzzleloaders that made the Hawkens famous were becoming obsolete, so Gemmer turned to breechloaders. He used factory actions but barrelled and stocked them in the same style as the Hawkens' well known muzzleloaders.
I have seen Gemmer Sharps original and reproduction pictured and shot alongside a Gemmer Trapdoor reproduction.