The other reason we're relaxed is that neither the house we're buying nor the one we're selling are putting a huge load on our finances. By spending a sensible amount on our home, which is a form of consumption, we can afford to invest a reasonable slice of our income.
If we'd gone for the €750,000 house in a fashionable part of town rather than the much cheaper one in a respectable part of town we couldn't afford to invest or save anything. Or eat.