Value -
Value is another very subjective topic. What is expensive to some might be a deal to others. You can look at this topic in multiple ways. One is raw price and the other is what you get for the money. Each is accurate and both are correct ways to look at price/value. We tend to look at features, performance and real-property when we discuss value. However, we also take into account the raw cash cost of the item.
The PowerSkin is available on Amazon.com, but nowhere else at the time of this writing. PowerSkin did have their own online store but as you can see, it is offline right now. Once you can locate the PowerSkin for EVO 4G it will set you back around $60. This is par for the course with these case/battery combinations. After all you are getting a $30+ case and an extended batter (which is about another $30) so it is not that bad of a deal in terms of what you are getting.
Performance wise you are getting what you pay for. For $60 you are getting almost double the life off the stock battery. There are some factors that take away from the value, there is the issue of heat that still worries me and that means you will have to change the way you use your EVO. Because of this I have to say that I do not think the PowerSkin for the EVO is worth the full $60 at this time. I cannot speak for other products (for other phones) though as they have different thermal profiles and operating ranges.
Conclusion -
The PowerSkin is a product that enters a market that is filled with others all vying for the same fickle market. The one thing they have going for them is that they are not sticking with single product lines but are working to expand to other phones and are not sticking with Apple only like many others in this game. We have taken a look at a single aspect of this company; the EVO 4G case. We came away with mixed feelings though. The PowerSkin for EVO 4G does give you excellent battery life. This comes at a cost in weight, bulk and heat. These are three things that most people would not want in their smart phone. After all we have been trying to get smaller, lighter and cooler why go back the other way. To put things bluntly, the PowerSkin Silicone Battery case for the THC EVO 4G is a product that had great promise but certain things about it prevent us from recommending it to any EVO 4G Owner.