There are a lot of things I have learned over the years about shopping. The biggest one is that quality will save you money in the long run. Sometimes, you really do get what you pay for, and if one can use a pricier item for a longer period of time than a cheaper item, the pricier item becomes cheaper per use.
My big item example. I use my vacuum for everything. I have carpet, hard floors, rugs and furniture. I have ceiling fans, surfaces that collect dust and too many animals that shed. After using a number of cheap and expensive vacuums, I have to say it was worth every extra penny to purchase my Kenmore. It has the long hose and extension I need for dusting. I can turn the beater bar on and off easily when I go from carpet to hard floor. It is powerful enough to pick up dog hair and cat litter from anywhere which is vital in my house. I also know from my last 15+ year old Kenmore that they last a very long time. I know I sound like an ad, but I have a point. I paid $200 for my Kenmore. It isn't the "best" one available, but it had the important features I wanted. $200 is still a lot of money when you are living on a budget. However, before this I went through a $40 Dirt Devil, a $60 Scunci, and a $120 Eureka. The dirt devil lasted a year. The scunci lasted less than 6 months. The Eureka lasted 2 years. On average, I was running $40-120 a year on vacuums and quite frankly, not one of them worked as well as the Kenmore I had before, which I got when it was 10 years old, and I put another 5 years on it before it was no longer worth it to fix it.
Now, I don't know many who need $800 top of the line vacuums, but a mid line will save me money in the long run. If this vacuum runs for 10 years, I will have spent $20 per year on a vacuum. That is way below my current batting average.
The same principles can be said for a number of smaller items. Cheap scoopable cat litter can not be used as long, and does not clump or block smells like some of the leading brands. It ends up being cheaper for me to buy Tidy Cat or Fresh Step on sale with a coupon than to get the dollar store cat litter. CFL bulbs last much much longer than traditional bulbs. I have not changed a light bulb in over 2 years. Even without the energy savings, the CFL bulbs end up being cheaper.
There are things that store brands are great for. I am all about getting the best deal. However, sometimes getting the best deal means paying more money now to get the savings later.