As a professional cheapskate, I have an allergic reaction whenever I pay more for something than I think it's really worth. But there have been a few times when I've attempted to economize and later regretted it. Here's my Top Six List of Frugality Gone Wrong:
Wimpy power tools: As a general rule of thumb, I've found that it always pays to buy the best tools you can afford at the time. This is true not only of power tools, but also hand tools and other tools you use in the garden, kitchen, and around the house. In my experience, there tends to be direct correlation between the quality/lifespan of a tool and how much it costs. By spending more upfront, your do-it-yourself projects will be easier and turn out better, inspiring you to take on even more projects yourself.
Cheap plastic wrap: While I know for a fact that there are many true bargains to be had at "dollar stores," anytime I've bought plastic wrap there for a buck I've been disappointed. Definitely ultra-flimsy, hard to get off the roll, and lacking in cling-ability. By the way, save your disposable "shower cap" next time you stay at a hotel - they make great covers for plates of leftovers and other containers in the fridge.
House paint: The can of bargain-priced, off-off-off-brand paint I bought said "cleans up is easy, just use soap and water." Unfortunately, every passing rainstorm seems to be cleaning it right off the side of the house as well. Given the investment of time and/or money that goes into painting your house - and the value of the asset you're protecting - always spring for top quality paint.
Walking shoes and socks: I'm not talking about wasting money on "designer athletic shoes." But if you're a serious walker/hiker like me, you get what you pay for (or don't pay for) when it comes to investing in a well-made pair of walking shoes and proper socks to go with them. I have the blisters to prove it from the times I've bought cheaper shoes in the past.
Landscaping plants: It's certainly possible to find some real bargains on landscaping plants, particularly at the end of the season. But the important thing to remember is that when you invest in perennial plants for your yard, they're likely to outlive you. Make sure it's a plant you really like - and want to have in your yard for many years to come - and not just "a good bargain."
Half-priced oysters on the half-shell: I love raw oysters, even though I know there are health risks associated with eating raw or undercooked seafood. But I can tell you one thing from personal experience: If you see oysters on the half-shell marked down to half-price on the little chalkboard in front of one particularly seedy waterfront café in Miami, Fla., just keep on walking. It was truly a gut-wrenching experience.
Photo by ClintJCL via Flickr Creative Commons