Value is subjective...I could tell you what it's worth from a book I own, but that doesn't mean the buyer standing in front of you, or the shop owner who needs to buy and sell for a profit, will be willing to pay that amount.
If you want a starting price...
The Model 1890 was made from 1890 to 1932 and came in three different Models and two Grades: Standard and Deluxe...and if correctly dated to
1898 is considered a Third Model ( Standard ?) and is worth $900 in Good condition and $450 for Fair.
The Model 12 was made in different grades: Standard, Featherweight, Riot Gun, Trench Gun, Skeet Grade, Trap Grade, Pigeon Grade, and Heavy Duck Gun...and barrel lengths. Prices vary greatly depending on how rare that grade was ( amount made ) in it's 51 year history.
As far as Gunbroker, Guns America, Craigslist and Ebay...never used them.
While .22 long rifle and .22 magnum are the norm, most
small gun shops in my area also carry .22 long and .22 short.
A quick search of the internet provided this site...
http://ammo-sale.com/products.asp?cat=9497If you appreciate the amount of info and time I put into this answer, please click on the PLUS (+) sign under my name to show your gratitude. Thank you !