Taurus makes pretty decent revolvers, and they're reliable.
Depending on condition, about $250-$300.
You will have to call Taurus to find out.
It is possible.
A fine revolver.
No such caliber in the S&W line.
25-125
Depends on how old the revolver is.
Made in 1982.
go to kbb.com
100-1000 usd
You can find a 22 mag cylinder for a 22 mag revolver mod 21S MIW Germany on eBay. You may also be able to find one through antique sales and antique gun collectors.
100-1000 depending on specifics