We all need stuff. So buying the products is part of our life and when we say frugal living, it certainly doesn't mean that u live cheaply, it only means u live reasonably within Ur means.
But every product has so many different brands available that I can hardly decide. And over the period of time, my accumulated golden principles for buying one particular brand is:
1) Compare the maintenance cost and buy with the least of them, even if this means buying little expensive item at first place. It pays in long term. I remember me and my friend once bought some electronic item together. It cost him Rs 5000 and me Rs 7000. But in long run, on same usage, mine consumes electricity worth Rs 100 and his Rs 180 per month. So eventually my extra Rs 2000 are compensated in 25 (2000/80) months. And if I am going to use that product for around 10 years, I have definitely the best value for my money.
2) List the features available in all the products and make a separate list of the features you want to have. Only buy the product that has features closer to your list, reason, why to pay for features that you any how not going to use much!
I hope my 2 golden principles will help you too. :)