As someone who did exactly what we're talking about here, prices were not "very high" when I got my low interest loan. They're higher now than when I purchased 6 years ago, that's for sure. I don't know what else to say about that, or how to say it differently, as I've stated this several times now.
Lower interest rates do not enable longer loans, at least not in the US. You can always get 10, 15, and 30 year fixed loans. They also don't enable you to borrow more, not here. The amount you can borrow is based on your income and credit score, current interest rates are generally not a factor.