Patience and Research
Pay cash and don't buy junk. Buy quality and take good care of it. I'm still driving a 13-year-old 4-Runner with 200,000+ miles on it. My wife tells folks I'll be buried in it. It still runs great, so she may be right.
Use plastic for convenience, not for credit. If you don't have the money in the bank to pay off the card account in full, don't make the purchase. Be patient.
Don't worry about what other folks have. If it's not yours, it doesn't matter. They don't pay for your stuff - you do.
Buy factory rebuilt power tools - same as new but costs less. Do your own projects and maintenance - you might be surprised to find that most of the work needed around the house/yard doesn't require special skills, just the right tools.
Spend some time researching before buying - Google is a great resource. So is Consumer Reports. Once again, be patient. New isn't necessarily better, just newer. (That is especially true with firearms.)