The marketability of their parts means that there are a lot of legally-owned Hondas which, of course, need parts replaced at times. And because everyone knows there are a lot of Hondas, the owners know it's easy to find a second-hand part from a junkyard or ebay to save money and thus for Hondas there exists a particularly lively market for old parts.
I always buy second-hand parts whenever it makes sense. It doesn't work that well with less popular cars, obviously. Either there aren't second-hand replacements that are easy to find or they're still too expensive (because of said scarcity...) so it makes sense to buy a new replacement part with warranty.
