Dynamically generated pages place more load on your Web server. You might need to upgrade your hosting plan or even contemplate a move to a dedicated server. Do try packaged solutions. It's almost always cheaper to buy and adapt an existing software package than to build from scratch. As software for data-driven sites becomes widely available, an increasing number of packaged solutions can meet common needs.
Shopping carts are a prime example.
If the only reason you require a database is to maintain an online catalog, some excellent e-commerce packages will do the job. Do invest in proper data analysis before you start. In reality, it's too easy to create a poorly designed database that is difficult to work with and to maintain. It's well worth paying for expertise up front to avoid these problems. Do check qualifications of the designer or the consultant you choose.