I am doing mod_perl based database driven web sites some of which have virtually no static content. I do all my own database design work.
I would recommend being really specific in your expectations about the database stuff. Do you need someone who can query an existing database, ie. look at the schema and make up their own queries, or a DBA type person who can lay out nicely normalized tables and build the database 'from the ground up' so to speak. I would expect the first to come for less compansation than the last.
Also this sounds like a strictly contract type job which tends to also up the ante.
Also I would recommend trying to get someone who will use some sort of temaplating system for the HTML and style sheets so you don't need another programmer just to tweak the look of a page a bit in the future.