There are many strategies for frugality: Don't buy stuff you don't need. Stock up when you get a good price. Make smart decisions about when to pay up for quality and when to get the cheap stuff. Then there's what I call ruthless frugality: Always getting the best price.
I'm not talking about stupid frugality — buying the cheapest shoes you can find even though they hurt your feet. Nor am I talking about shopping around, using coupons, and so on. Rather, I'm talking about getting the best price you can without regard for what's behind the great price.
At the extreme, of course, there's criminal frugality — buying stolen goods and pretending to believe that they fell off the back of a truck. But short of that, there are all sorts of things that enter the general stream of commerce at prices that embed lots of bad practices — stuff made in sweatshops by children or prisoners or slaves, stuff made in ways that poison the workers or trash the environment.
Most people delegate to the government the job of policing how things are produced. There are, for example, laws about how farm animals have to be treated, and most people hope that those laws are strict enough that the food produced is safe and the animals' suffering is minimized.
But it's worth thinking about the costs of ruthless frugality. One good reason to pay more than you need to is to be a good neighbor, such as by buying locally. Patronizing local shops often costs more, but part of the reason the big box stores are cheaper is because they've got competition. Let all the local stores die and you can expect to see prices rise at the chain stores. More important, money spent in local stores tends to stay in town — possibly getting spent on stuff that you make or services that you provide. Perhaps more important yet, local production is often more ethical and more sustainable.
I talk about voluntary simplicity as being an essentially hedonistic lifestyle, because a high overall level of frugality frees up resources that can go to those specific areas of your life where paying more makes a difference that matters to you. The upside of frugality is more of what you care about.
I think a little hedonism is great, when it is enabled by thoughtful choices about priorities. But I think a similar amount of thinking ought to go into where really cheap stuff comes from — and whether your values can support the ruthlessness built into the price.