H&R Bean cobb price quest.(newbie)

i have a chance to buy a couple in absolutlty mint condition whith 1 key, and the orgiginal box for them, the box has the H&R logo and patent date on it , think the date was around 1899 or something like that.in the box is alos an envelope or something like that, i have never own something like this before,so my question is, how much i should pay for them, or how much it could be worth in this condition.