Railpass for Benelux/Germany

If you're set on doing a railpass, it doesn't really matter if you buy it in advance or in person at a train station. The better question is if a railpass is the best option for your itinerary, which you can only find out by comparing point to point tickets for your dates/routes.

"If you're set on doing a railpass, it doesn't really matter if you buy it in advance or in person at a train station." Except that not all Eurail passes are sold in Europe, and Germany/Benelux is not one that is. Read here. "or purchase while I am there?" Purchase what? If a rail pass, read above. If point-point tickets, probably better. Your destinations in Germany are not far from Benelux, so the point-point ticket prices would probably not be that much.

Sorry, I should have been clearer on that...point to point as needed while I am there.

Well, ain't that a kick in the nuts, that they don't sell all passes in Europe. I'd purchased a Germany-France pass in Europe. Anyway if you're doing p2p tickets, you will save money if you buy them ahead of time online. You'll need to use the national rail websites of the countries you'll be traveling in to price out your tickets and compare with the price of a railpass.