Should I get an appraisel of my Tudor BB 58 from AD?

[cronos]

I got this email from the lady at the AD who sold me my new Tudor BB 58:

"Happy New Year to you! How is your TUDOR watch?
Would you like an appraisal for insurance purposes?"

I hadn't thought about this before because this is the first watch I have bought that is worth more than a couple hundred dollars. Should I insure it? Do I need an appraisal if I already have a sales receipt? Does it cost money to get an appraisal from the AD I just bought the watch from? Any advice you could give this newbie would really be appreciated.