Try Adobe Software for Free
Not sure if you need Photoshop Extended or if Photoshop Elements would be fine? Photoshop Elements is definitely easier on the budget so if you could use that instead wouldn't you? Or maybe you are thinking about migrating to Dreamweaver from Frontpage but not sure about the learning curve and if you could be up to speed by time school starts back in the fall.
Adobe offers free 30-day trials of almost all of their software. This is a huge advantage that I find comes as a surprise to educators all the time!
http://www.adobe.com/downloads/
They also offer free training -- in the form of online videos -- that can get you moving really quickly.