I think it would be a good idea to do no printed manual but only include it as a PDF .
I e.g. always play dominions with opened MIQR , SCQR , Magiboost.xls , Unitattributes.xls and units.xls .
Sometimes a few more rarer needed additional documents
.
So the PDF would serve 2 goals :
1. searchable documents , so you find the info you need easy . A book has just no searching options so a long printed manual is inferior to a PDF or similiar with good searching options .
2. This would decrease the costs for producing dominions 3 . I don't know how much the dominions 2 manual costed but my guess is that it costed at least 5 times more then the CD .
This way you could hopefully offer dominions 3 for 40€ and not for 50€ . Then more ppl will buy it and you will make a bigger profit as well .
While i e.g. bought RTW instantly for 40€ i considered much more if i should buy Battle for Middleearth as well which costed 55€ .
I think especially in the PC gaming market 40€ is a magical border and there is another , more eLastic aggregate demand formula for prices >40€ then for prices <40€ .