a 400 dollar pen doesn't have to be ostentatious. and can be a conservative looking black or silver pen, but the mechanics of the parts within the pen is what may make it seem ostentatious to some, but those would only be to people who know a lot about pens to begin with. which in means that this pen would be noticed by other connoisseurs which will instantly help first impressions between the two conoisseurs which could spawn a great business relationship.
this also applies to watches; there are more people who like watches then pens which means more people will notice the watch which means. the guy with the international watch company watch sees a person with a breguet tourbillion lets say, then that may be ostentatious because the guy with the IWC knows how expensive it is, but will also want to make you meet that person and see what kind of business they are in, the watch will become a conversation starter.
if you're trying to argue that image isn't everything and if you think this is appropriate logic, then an off the rack untailored suit would suffice over a bespoke made suit and you would see less men paying attention to the quality of their suits.
