If you intend to travel only Paris - Salzburg - Munchen - Nurenberg - Berlin - Hamburg there is absolutely no need to purchase any type of pass. Regular tickets will be much cheaper.
1) Paris-Salzburg can be done cheap enough with a help of buying in advance via
www.tgv-europe.com (roughly even regular everyday tariff would be around 100 euro).
2) Salzburg-Munich can be easily done for 20 euro with a help of Bavaria ticket (see our Germany page for more info).
3) Same Bavaria ticket works for Munich-Nuernberg leg too.
4) Nuernberg-Berlin and Berlin-Hamburg legs can be done for 29 euro each (purchasing via DB website some time in advance).
So even roughly you can manage the whole trip for app.200 euro. As you can see no need to purchase 300 euro pass.
p.s In case you are willing to switch overnight trip for late afternoon-evening one you can travel even for 39 euro from Paris to Salzburg (buying discounted ticket from DB), then you total travel expenses can be cut up to 140 euro.