A solid video doorbell with a local hub keeps your footage private and avoids ongoing cloud subscription fees. Aim for a model that has been out for at least six months so you aren't paying the premium for a brand-new release that might still have software bugs.
When autumn sales hit, older hardware often gets bundled with extra mounts or power kits. Buying a kit that includes everything you need means you won't have to go back to the store for parts, making your investment last several years instead of just one.
That 18-month window is a deadline, not free money. If you have a balance left when it ends, the bank will charge you interest on what you still owe at their standard rate.