Keep track of your product warranties.
I'm not necessarily advocating the purchase of "extended" warranties, but keep track of the manufacturer's warranty.
Cindy and I purchased a kitchen sink faucet about 12 years ago (not cheap) and it recently started dripping when shut off. I took pictures of the item and emailed the manufacturer's customer service department. They emailed me today stating that the item has a lifetime warranty and they were shipping me the replacement cartridge that will fix it for free. Also, our Quickset front door handle broke a few months ago. We've priced a new one and they cost at least $75+. While shopping for a replacement we saw that what we already have has a lifetime warranty. I called them today, emailed pictures and they're sending me a brand new one at no charge. Those 2 things alone will save me lots of $$$.