Point to Point Rail Fares

try eurail.com. you can put in the cities and it will give you prices. you can also try sta travel (statravel.com) they have youth and student deals but im pretty sure they also have full fare.
Another good place to look is rick steves rail pass store. go to point to point tickets and he lists websites for each country. i copied and pasted the germany and france part for you:

Germany: http://bahn.hafas.de/bin/query.exe/en Best source for train schedules throughout Europe. Sells tickets for Germany, normally at full fare, with a few last-minute or web-only deals on just a few seats. German trains run frequently and don't need reservations (except overnights), so it's easier to buy tickets in the station (or consider a railpass).

France: www.tgv.com or www.sncf.com Good discounts for advance-purchase, youths, seniors, families, and off-peak and roundtrip travel. Tickets go on sale 90 days in advance and the best rates sell out early. TGV trains require reservations before boarding and do fill up, so order as soon as you can commit to a travel time. Follow the TGV link for English language and non-French residents. Print tickets at home (a few fares) or pick up in the station. If you select USA delivery, you'll be re-directed to Rail Europe, which offers similar prices, but not always the same. The SNCF link sells more train types but ordering is mostly in French.

Thanks Christy.
Started with the German website and it has all the info and fares that I needed to make the comparison.
A great link.