What is the value of an 1849 us dime?

Look on the back of the coin to see if there's a small mint mark letter. It may be blank or there may be an O.

Numismedia lists the following approximate retail values as of 07/2010:

No mint mark (Philadelphia):

Very worn condition - $13

Moderately worn - $18

Slightly worn - $30

Almost no wear - $193

Uncirculated - $390 to $4,940 depending on quality

"O" mint mark (New Orleans):

Very worn - $16

Moderately worn - $58

Slightly worn - $127

Almost no wear - $848

Uncirculated - $2,640 to $6,440