It's hard to tell without actually seeing the Bible. The following similar items were found on eBay. You might want to check out the sites because there are pictures of the Bibles there. It would seem that those printed in the 1800's that are in a foreign language might bring a higher price. Of course the condition of the Bible, number of copies printed and what a collector would be willing to pay also make huge differences as far as the possible worth in monetary terms.
My suggestion would be to take it to a bookstore that sells antique and collectible books, periodicals and magazines so that an expert can see it "live." This is just a guess, but I would say, that if it's one of those that were printed in the U.S., soft-bound in leather and about four inches wide to six inches in length, then it might be worth $5.00 to $15.00 depending on it's condition and the number of printings of it. If it has a lot of artwork in it, it may be worth considerably more. If it is hard-bound in leather, printed in the U.S., is large and in great condition, it could be worth hundreds or even more.
Antique 1836 for American Bible Society New Testament - (eBay item 140154836699 end time Sep-11-07 18:22:39 PDT)
Antique 1836 for American Bible Society New Testament Starting bid: US $9.99
Antiques: SCARCE German New Testament Bible 1896 - eBay, Other Books, Publications, Books, Publications, Antiques. (end time 29-Sep-07 14:37:24 AEST)
SCARCE German New Testament Bible 1896 AU $49.95
Antiques: SCARCE German New Testament Bible 1896 - eBay, Other Books, Publications, Books, Publications, Antiques. (end time 29-Sep-07 14:37:24 AEST)
ANTIQUE BIBLE NEW TESTAMENT CYRILLIC BOOK 1867 LUX US $3,100.00
ANTIQUE BIBLE NEW TESTAMENT CYRILLIC BOOK 1867 LUX - (eBay item 180151468655 end time Sep-20-07 02:57:46 PDT)