Wish I had a grading guide handy, I have 3 different ones and don't know where any of them are. Don't grade too many bust coins. Looks close to XF, but I'm going to say a high end VF.
My opinion is a value of $200 or a little more. Better detailed pics so the surface of the coin can be seen a little better would help. Look on eBay to see what other 1830 dimes are selling for.
Thanks for your replies. It's definately one of the best condition silvers I've found, and although I don't plan on letting it go, it's nice to have some idea of it's grade and value.