When a sunsun/aquatop/perfect can last 20+ years you might be able to make that claim, not knocking the thing in any way just sayin.
Well considering they have only been available for less then 5 years yes time will tell.
You must put into play that the Eheims come with all the media so your not saving that much, granted you could fill it with pot scrubbies but you can't deny Eheim produces top notch media along with the product.
Even still the cost of the media does not make up the approximately 100$ difference in cost. Eheim makes great products as the great majority of the other manufactures out there do or they would not still be in business.
There are many things that can be put into a canister other then purpose made materials that will work just as well for a fraction of the cost that have been well documented over the last few decades. It's up to the individual to think outside the box and do the research to find what they are or find new and inventive solutions with new materials as they become available.
As my old teacher used to say there is more then one way to skin a cat. (figuratively not literally)