I'm trying to find a good environment to build and maintain an existing website. Would Adobe's Dreamweaver be a good purchase for coding in PHP, html, jquery, with a MySQL database?
Dreamweaver is mostly a waste of money unless the site is static or static mixed with pages that have procedural PHP. And only then the only real features that make it somewhat worth the money are the templating/library item features.
If youre building something with an MVC architecture or using a full blown CMS youre better off an actual IDE (Netbeans, Eclipse, etc..) or a lightweight text editor (Textmate, E, Notepad++, Coda, etc..).