Actually what you're describing is called "add a pearl." It's generally done when building a pearl strand. Your budget more than allows a full strand, so my question is, why does this design appeal to you? Are you looking for half chain, half pearls? 2/3 pearls? There are several extender clasps which would give you some chain to work with and you'd also have the flexibility of wearing the strand short, long, or somewhere in between.
Pretty Panda pic by nlerner on her U.S. excursion last year, San Diego Zoo.[/SIZE][/SIZE]