* Universal equations that can be applied to all products or major categories of products for what is 'best' durable for long term use, including adjustments for value/price. Have to evaluate for self-repair vs pro repair. Availability and price of spare parts. Account for geographic location.
* To help sell the 'best' recommendation for subcategories of 'best', you could show other products that were close but are not the best. But to help users see 'best' in specific categories (ex. not best durable fridge, but best quietest fridge) you will need many custom filters. Some ideas to copy are the extensive filters on Digikey for say, an alum. electrolytic capacitor: https://www.digikey.com/en/products/filter/aluminum-electrol... or on McMasterCarr for a screw: https://www.mcmaster.com/screws
* A good test of 'best' durable in my mind, is answering the question: Would this product be the one chosen to go with the Mars colony ships? Is it fairly cheap, durable in all environments, easy to repair, easy to make spare parts, lasts a long time, low maintenance, etc?