I seriously doubt the average Ivy League/Oxbridge aspirant would ever consider a Germany university as an alternative. Below these few elite universities you have another upper tier which in the UK would be Imperial/UCL/Durham etc. (although some departments in this supposedly lower tier are superior to the top tier). Below that you have another tier, and looking at this tier in the global rankings you are starting to see some German universities crop up. Basically, and I'm not looking to be offensive, but with these universities your market is by definition the more mediocre students, and it is in this group that I think you would start to find students for whom price is more of a priority than quality. Students at the better than average universities expect their degree to deliver a premium that will easily wipe out the cost.