Not as such. They won't recieve a special message, but the price change will appear in their Watched Items List.
However, there is no reason to believe that anything will encourage a Watcher to become a Buyer.
Do your own comparison, including shipping costs, for your items. You can put them in YOUR Watch list and use Compare. Unless your prices are way out of line, I wouldn't change them.
FWIW, there is one item on my Watch list that has been there for over two years. The seller has multiples and it relists itself constantly. One of these days..... or not.....
