Support things that last a lifetime

When I need to buy a new product, I often research it in depth, to ensure I'm getting the best value for my money. For years my friends have been asking me what I recommend for a given product, as a result of this. I'd often thought about just making a website, and thus my product research would not be lost. I finally registered a domain and have started a website, called Last a Lifetime. The intention of this site is to be the opposite of planned obsolescence, but instead to support sustainable design when I research products pre-purchase in the future.
The challenge I've already come across, and would love your feedback on, is how can I objectively measure this to be the most useful?
One idea was also to consider environmental impact/green friendliness of the product, how local it is from the purchaser, and measure a score out of all of these factors. It turns out, this is difficult to do, objectively, across all purchasable products.
Even just in the "last a lifetime" metric, I've already hit a speed bump on my fifth product. I had a dishwasher stop working properly, and as I started my research I realized that the top 3 dishwashers are all well over $5,000 CAD. This is not cost effective for most. While I can see even as much as double the price of a regular dishwasher for one that would last a lifetime would be worth it, this is a hard thing to measure. I brought this challenge up at the Ideas - Vancouver meeting this week, and it was suggested that the site would be useful with just a written summary on my findings in these regards for a given product, and how I ended up at my final choice of three, and let the reader decide. While that is the current path, this is only useful if the reader has the exact same budget as me at a given time.
Do you have any suggestions on how to do such product research with the most benefit to the most Canadians saving you the time of researching the best choice based on which will likely last the longest?