As I'm sure you appreciate, Dreamweaver is not a help authoring tool. It can create web pages which on their own can be used as help pages. However having help pages does not constitute a help file. What about navigation? If you require a TOC, Index, Glossary or Search capability you'll need a help authoring tool like RoboHelp. Of course this is only scratching the surface of what a true help authoring tool can provide over just HTML pages. You can easily import HTML files created in Dreamweavor into RoboHelp and then create your TOC, Glossary, etc.
The RoboColum(n) @robocolumn Colum McAndrew
Colum indicated he was just scratching the surface. Two major points in favour of a HAT that I would throw in are conditional build tags so that you can exclude certain content and the ability to create different outputs. Dreamweaver will give you something for a web server, what about local forms of help and printed documentation? They may not matter to you but it's important you consider them rather than find out later.
See www.grainge.org for RoboHelp and Authoring tips
Totally understand about the Cost to Use ratio. A less expensive alternative you may wish to consider using is FAR.
Some folks may raise eyebrows about my mention of FAR because they may believe it's only for Find And Replace. Although it won't have all the bells and whistles of RoboHelp, it should assist with what you need because it may also be used as a HAT.
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